34 resultados para Alan T. Stutts
em CORA - Cork Open Research Archive - University College Cork - Ireland
Resumo:
This thesis studies contemporary poetry’s innovations in textual borrowing and the range and scope of its appropriative practices. The restrictions of the inherited definitions of appropriation include a limited capacity for expression and meaningfulness, a partial concept of appropriation’s critical capacity, and an inadequate sense of the poets individual and unique practice of appropriation. This thesis resolves the problematic constraints limiting contemporary definitions of appropriation by tracing the history of the practice to reveal an enduring relation between appropriation and poetic expression. Close readings of Trevor Joyce’s, Alan Halsey’s, and Susan Howe’s poetry serve as evidence of contemporary poetry’s development of appropriation beyond the current ascriptions and offer some direction on how the critical understanding of appropriation might be extended and redefined. Here, appropriation is recognized as another source of lyric expression, critical innovation, and conceptual development in contemporary poetry. This thesis encourages a new perspective on the purpose and processes of poetic appropriation and the consequences of its declarative potential for both poet and poem.
Resumo:
The objective of this paper is to investigate the effect of the pad size ratio between the chip and board end of a solder joint on the shape of that solder joint in combination with the solder volume available. The shape of the solder joint is correlated to its reliability and thus of importance. For low density chip bond pad applications Flip Chip (FC) manufacturing costs can be kept down by using larger size board pads suitable for solder application. By using “Surface Evolver” software package the solder joint shapes associated with different size/shape solder preforms and chip/board pad ratios are predicted. In this case a so called Flip-Chip Over Hole (FCOH) assembly format has been used. Assembly trials involved the deposition of lead-free 99.3Sn0.7Cu solder on the board side, followed by reflow, an underfill process and back die encapsulation. During the assembly work pad off-sets occurred that have been taken into account for the Surface Evolver solder joint shape prediction and accurately matched the real assembly. Overall, good correlation was found between the simulated solder joint shape and the actual fabricated solder joint shapes. Solder preforms were found to exhibit better control over the solder volume. Reflow simulation of commercially available solder preform volumes suggests that for a fixed stand-off height and chip-board pad ratio, the solder volume value and the surface tension determines the shape of the joint.
Resumo:
A wearable WIMU (Wireless Inertial Measurement Unit) [1] system for sports applications based on Tyndall's 25mm mote technology [2] has been developed to identify tennis performance determining factors, giving coaches & players improved feedback [3, 4]. Multiple WIMUs transmit player motion data to a PC/laptop via a receiver unit. Internally the WIMUs consist of: an IMU layer with MEMS based sensors; a microcontroller/transceiver layer; and an interconnect layer with supplemental 70g accelerometers and a lithium-ion battery. Packaging consists of a robust ABS plastic case with internal padding, a power switch, battery charging port and status LED with Velcro-elastic straps that are used to attach the device to the player. This offers protection from impact, sweat, and movement of sensors which could cause degradation in device performance. In addition, an important requirement for this device is that it needs to be lightweight and comfortable to wear. Calibration ensures that misalignment of the accelerometer and magnetometer axes are accounted for, allowing more accurate measurements to be made.
Resumo:
The goal of this work is to fabricate robust, highly-miniaturised, wireless sensor modules that incorporates ion-selective electrodes (ISEs). pH is one of the main parameters in assessment of the quality of our environment (water, soil) and these ISE/pH sensors will be deployed in a miniaturised, programmable modular system. The simplicity of ISEs (low costs and low power requirements) allow for the preparation of sensors that are all very similar in construction but can at the same time be easily made for variety of different environmentally important ions (i.e. heavy metals). This is important because of the increasing focus on the impact of the quality of the environment on society, both locally, and globally. The work described will contribute to a widely distributed sensor network for monitoring the quality of our environment, focused mainly on soil and water quality.
Resumo:
This paper reports on the design and the manufacturing of an integrated DCDC converter, which respects the specificity of sensor node network: compactness, high efficiency in acquisition and transmission modes, and compatibility with miniature Lithium batteries. A novel integrated circuit (ASIC) has been designed and manufactured to provide regulated Voltage to the sensor node from miniaturized, thin film Lithium batteries. Then, a 3D integration technique has been used to integrate this ASIC in a 3 layers stack with high efficiency passives components, mixing the wafer level technologies from two different research institutions. Electrical results have demonstrated the feasibility of this integrated system and experiments have shown significant improvements in the case of oscillations in regulated voltage. However, stability of this output voltage toward the input voltage has still to be improved.
A simulation-based design method to transfer surface mount RF system to flip-chip die implementation
Resumo:
The flip-chip technology is a high chip density solution to meet the demand for very large scale integration design. For wireless sensor node or some similar RF applications, due to the growing requirements for the wearable and implantable implementations, flip-chip appears to be a leading technology to realize the integration and miniaturization. In this paper, flip-chip is considered as part of the whole system to affect the RF performance. A simulation based design is presented to transfer the surface mount PCB board to the flip-chip die package for the RF applications. Models are built by Q3D Extractor to extract the equivalent circuit based on the parasitic parameters of the interconnections, for both bare die and wire-bonding technologies. All the parameters and the PCB layout and stack-up are then modeled in the essential parts' design of the flip-chip RF circuit. By implementing simulation and optimization, a flip-chip package is re-designed by the parameters given by simulation sweep. Experimental results fit the simulation well for the comparison between pre-optimization and post-optimization of the bare die package's return loss performance. This design method could generally be used to transfer any surface mount PCB to flip-chip package for the RF systems or to predict the RF specifications of a RF system using the flip-chip technology.
Resumo:
A comparison study was carried out between a wireless sensor node with a bare die flip-chip mounted and its reference board with a BGA packaged transceiver chip. The main focus is the return loss (S parameter S11) at the antenna connector, which was highly depended on the impedance mismatch. Modeling including the different interconnect technologies, substrate properties and passive components, was performed to simulate the system in Ansoft Designer software. Statistical methods, such as the use of standard derivation and regression, were applied to the RF performance analysis, to see the impacts of the different parameters on the return loss. Extreme value search, following on the previous analysis, can provide the parameters' values for the minimum return loss. Measurements fit the analysis and simulation well and showed a great improvement of the return loss from -5dB to -25dB for the target wireless sensor node.
Design and implementation of the embedded capacitance layers for decoupling of wireless sensor nodes
Resumo:
In this paper, the embedded capacitance material (ECM) is fabricated between the power and ground layers of the wireless sensor nodes, forming an integrated capacitance to replace the large amount of decoupling capacitors on the board. The ECM material, whose dielectric constant is 16, has the same size of the wireless sensor nodes of 3cm*3cm, with a thickness of only 14μm. Though the capacitance of a single ECM layer being only around 8nF, there are two reasons the ECM layers can still replace the high frequency decoupling capacitors (100nF in our case) on the board. The first reason is: the parasitic inductance of the ECM layer is much lower than the surface mount capacitors'. A smaller capacitance value of the ECM layer could achieve the same resonant frequency of the surface mount decoupling capacitors. Simulation and measurement fit this assumption well. The second reason is: more than one layer of ECM material are utilized during the design step to get a parallel connection of the several ECM capacitance layers, finally leading to a larger value of the capacitance and smaller value of parasitic. Characterization of the ECM is carried out by the LCR meter. To evaluate the behaviors of the ECM layer, time and frequency domain measurements are performed on the power-bus decoupling of the wireless sensor nodes. Comparison with the measurements of bare PCB board and decoupling capacitors solution are provided to show the improvement of the ECM layer. Measurements show that the implementation of the ECM layer can not only save the space of the surface mount decoupling capacitors, but also provide better power-bus decoupling to the nodes.
Resumo:
Colour is everywhere in our daily lives and impacts things like our mood, yet we rarely take notice of it. One method of capturing and analysing the predominant colours that we encounter is through visual lifelogging devices such as the SenseCam. However an issue related to these devices is the privacy concerns of capturing image level detail. Therefore in this work we demonstrate a hardware prototype wearable camera that captures only one pixel - of the dominant colour prevelant in front of the user, thus circumnavigating the privacy concerns raised in relation to lifelogging. To simulate whether the capture of dominant colour would be sufficient we report on a simulation carried out on 1.2 million SenseCam images captured by a group of 20 individuals. We compare the dominant colours that different groups of people are exposed to and show that useful inferences can be made from this data. We believe our prototype may be valuable in future experiments to capture colour correlated associated with an individual's mood.Colour is everywhere in our daily lives and impacts things like our mood, yet we rarely take notice of it. One method of capturing and analysing the predominant colours that we encounter is through visual lifelogging devices such as the SenseCam. However an issue related to these devices is the privacy concerns of capturing image level detail. Therefore in this work we demonstrate a hardware prototype wearable camera that captures only one pixel - of the dominant colour prevelant in front of the user, thus circumnavigating the privacy concerns raised in relation to lifelogging. To simulate whether the capture of dominant colour would be sufficient we report on a simulation carried out on 1.2 million SenseCam images captured by a group of 20 individuals. We compare the dominant colours that different groups of people are exposed to and show that useful inferences can be made from this data. We believe our prototype may be valuable in future experiments to capture colour correlated associated with an individual's mood.
Resumo:
The multiquantum barrier (MQB), proposed by Iga et al in 1986, has been shown by several researchers to be an effective structure for improving the operating characteristics of laser diodes. These improvements include a reduction in the laser threshold current and increased characteristic temperatures. The operation of the MQB has been described as providing an increased barrier to electron overflow by reflecting high energy electrons trying to escape from the active region of the laser.This is achieved in a manner analogous to a Bragg reflector in optics. This thesis presents an investigation of the effectiveness of the MQB as an electron reflector. Numerical models have been developed for calculating the electron reflection due to MQB. Novel optical and electrical characterisation techniques have been used to try to measure an increase in barrier height due to the MQB in AlGaInP.It has been shown that the inclusion of MQB structures in bulk double heterostructure visible laser diodes can halve the threshold current above room temperature and the characteristic temperature of these lasers can be increased by up to 20K.These improvements are shown to occur in visible laser diodes even with the inclusion of theoretically ineffective MQB structures, hence the observed improvement in the characteristics of the laser diodes described above cannot be uniquely attributed to an increased barrier height due to enhance electron reflection. It is proposed here that the MQB improves the performance of laser diodes by proventing the diffusion of zinc into the active region of the laser. It is also proposed that the trapped zinc in the MQB region of the laser diode locally increases the p-type doping bringing the quasi-Fermi level for holes closer to the valence band edge thus increasing the barrier to electron overflow in the conduction band.
Resumo:
The genetics and biochemistry involved in the biodegradation of styrene and the production of polyhydroxyalkanoates in Pseudomonas putida CA-3 have been well characterised to date. Knowledge of the role played by global regulators in controlling these pathways currently represents a critical knowledge gap in this area. Here we report on our efforts to identify such regulators using mini-Tn5 transposon mutagenesis of the P. putida CA-3 genome. The library generated was subjected to phenotypic screening to identify mutants exhibiting a reduced sensitivity to the effects of carbon catabolite repression of aromatic pathway activity. Our efforts identified a clpX disrupted mutant which exhibited wild-type levels of growth on styrene but significantly reduced growth on phenylacetic acid. RT-PCR analysis of key PACoA catabolon genes necessary for phenylacetic acid metabolism, and SDS-PAGE protein profile analyses suggest that no direct alteration of PACoA pathway transcriptional or translational activity was involved. The influence of global regulators affecting the accumulation of PHAs in P. putida CA-3 was also studied. Phenotypic screening of the mini-Tn5 library revealed a gacS sensor kinase gene disruption resulting in the loss of PHA accumulation capacity in P. putida CA-3. Subsequent SDS-PAGE protein analyses of the wild type and gacS mutant strains identified post-transcriptional control of phaC1 synthase as a key point of control of PHA synthesis in P. putida CA-3. Disruption of the gacS gene in another PHA accumulating organism, P. putida S12, also demonstrated a reduction of PHA accumulation capacity. PHA accumulation was observed to be disrupted in the CA-3 gacS mutant under phosphorus limited growth conditions. Over-expression studies in both wild type CA-3 and gacS mutant demonstrated that rsmY over-expression in gacS disrupted P. putida CA-3 is insufficient to restore PHA accumulation in the cell however in wild type cells, over-expression of rsmY results in an altered PHA monomer compositions.
Resumo:
Globally, agriculture is being intensified with mechanization and increased use of synthetic fertilizers and pesticides. There has been a scaling up of production to satisfy the demands of supermarket distribution. Problems associated with intensification of production, trade globalisation and a larger market demand for greater volumes of fresh produce, include consumers' concern about pesticide residues and leaching of nutrients and pesticides into the environment, as well as increases in the transmission of human food-poisoning pathogens on raw vegetables and in fruit juices. The first part of this research was concerned with the evaluation of a biological control strategy for soil-borne pathogens, these are difficult to eliminate and the chemicals of which the most effective fumigants e.g. methyl bromide, are being withdrawn form use. Chitin-containing crustaceans shellfish waste was investigated as a selective growth substrate amendment in the field, in glasshouse and in storage trials against Sclerotinia disease of Helianthus tuberosus, Phytophthora fragariae disease of Fragaria vesca and Fusarium disease of Dianthus. Results showed that addition to shellfish waste stimulated substrate microbial populations and lytic activity and induced plant defense proteins, namely chitinases and cellulases. Protective effects were seen in all crop models but the results indicate that further trials are required to confirm long-term efficacy. The second part of the research investigated the persistence of enteric bacteria in raw salad vegetables using model food poisoning isolates. In clinical investigations plants are sampled for bacterial contamination but no attempt is made to differentiate between epiphytes and endophytes. Results here indicate that the mode isolates persist endophytically thereby escaping conventional chlorine washes and they may also induce host defenses, which results in their suppression and in negative results in conventional plate count screening. Finally a discussion of criteria that should be considered for a HACCP plan for safe raw salad vegetable production is presented.
Resumo:
The development of procedures and media for the micropropagation of B. rex are described. Media for the production of plantlets from a number of other Begonia hybrids are also provided. Growth analysis data is given for plants produced in vivo from leaf cuttings and in vitro from mature leaf petioles and immature leaves derived from singly and multiply recycled axenic plantlets. No significant difference was found in phenotype or quantitative vegetative characters for any of the populations assessed. The results presented from studies on the development of broad spectrum media for the propagation of a number of B. rex cultivars using axenic leaf explants on factorial combinations of hormones illustrate the major influence played by the genotype on explant response in vitro and suggest media on which a range of B. rex cultivars may be propagated. Procedures for in vitro irradiation and colchicine treatments to destabilize the B. rex genome have also been described. Variants produced from these treatments indicate the utility of in vitro procedures for the expression of induced somatic variation. Colour variants produced from irradiation treatment have been cultured and prove stable. Polyploids produced as variants from irradiation treatment have been subcultured but prove unstable. Media for the induction and proliferation of callus are outlined. The influence of callus subculture and aging on the stability of the B. rex genome is assessed by chromosomal analysis of cells, in vitro and in regenerants. The B. rex genome is destabilized in callus culture but attenuation of variation occurs on regeneration. Diploid cell lines are maintained in callus subcultures and supplementation of regenerative media with high cytokinin concentrations, casein hydrolysate or adenine failed to produce variants. Callus aging however resulted in the production of polyploids. The presence and expression of pre-existing somatic variation in B. rex pith and root tissue is assessed and polyploids have been produced from pith tissues cultured in vitro. The stability of the B. rex genome and the application of tissue culture to micropropagation and breeding of B. rex are discussed.
Resumo:
Marine sponges (phylum Porifera) are the oldest extant metazoan animals on earth and host large populations of symbiotic microbes: Bacteria, Archaea and unicellular Eukaryota. Those microbes play ecological functions which are essential to the health of the host including carbon, nitrogen and sulfur cycling as well as host defence through the production of bioactive secondary metabolites which protect against infection and predation. The diversity of sponge-associated microbes is remarkable with thousands of OTUs reported from individual sponge species. Amongst those populations are sponge-specific microbes which may be specific to sponges or specific to sponge species. While marine natural product discovery concerns many animal phyla, Porifera account for the largest proportion of novel compounds. Evidence suggests that many of these compounds are the products of symbiotic microbes. Descriptions of sponge-associated microbial community structures have been advanced by the development of next-generation sequencing technologies while the discovery and exploitation of sponge derived bioactive compounds has increased due to developments in sequence-based and function-based metagenomics. Here, we use pyrosequencing to describe the bacterial communities associated with two shallow, temperate water sponges (Raspailia ramosa and Stelligera stuposa) from Irish coastal waters and to describe the bacterial and archaeal communities of a single sponge species (Inflatella pellicula) from two different depths in deep waters in the Atlantic Ocean, including at a depth of 2900m, a depth far greater than that of any previous sequence-based sponge-microbe investigation. We identified diverse microbial communities in all sponges and the presence of sponge-specific taxa recruiting to previously described and novel spongespecific clusters. We also identified archaeal communities which dominated sponge-microbe communities. We demonstrate that sponge-associated microbial communities differ from seawater communities indicating host selection processes. We used sequence-based metagenomic techniques to identify genes of potential industrial and pharmacological interest in the metagenomes of various sponge species and functionbased metagenomic screening in an attempt to identify lipolytic and antibacterial activities from metagenomic clones from the metagenome of the marine sponge Stelletta normani. In addition we have cultured diverse bacterial species from sponge tissues, many of which display antimicrobial activities against clinically relevant bacterial and yeast test strains. Other isolates represent novel species in the genus Maribacter and require emendments to the description of that genus.
Resumo:
This work examines the origins and early history of the Queen's College, Cork. Designedly there is as much stress on the origins as on the early history, for it is the contention of the work that the College was something more than a legislative mushroom. It was very much in the tradition of the civic universities which added an exciting new dimension to academic life in these islands in the nineteenth century. The first chapter surveys university practice and thinking at the opening of the century, relying exclusively on published sources. The second chapter is devoted specifically to the state of learning in Cork during the period, and makes extensive use of hitherto unpublished manuscript material in relation to the Royal Cork Institution. The third chapter deals with the highly significant evidence on education embodied in the Report of the Select Committee on Irish Education of 1838. This material has not previously been published. In chapter four an extended study is made of relevant letters in the manuscript correspondence of Sir Robert Peel - even the most recent authoritative biography has ignored this material. The remaining three chapters are devoted more specifically to the College, both in the formulation or policy and in its practical working. In chapter six there is an extended survey of early College life based exclusively on hitherto unpublished manuscript material in the College Archives. All of these sources, together with incidental published material, are set out at the end of each chapter.