Thesis (MTech (Oceanography))Cape Peninsula University of Technology, 2010 / The current dynamics along the Tsitsikamma coast is described from a combination of acoustic current measurements. satellite-tracked surface drifters and underwater temperature recordings made between November 2006 and March 2008. The Tsitsikamma coast is largely a Marine Protected Area (MPA) that protects a rich marine biodiversity. The nearshore currents are important in the dispersal of eggs and larvae of many marine species. including the paralarvae of the commercially caught chokka squid. LoNgo reynaudii. Changes in the environment, including the currents. can affect the successful recruitment of chokka squid, and can bring about large annual fluctuations in biomass that creates economic uncertainty in the squid fishery. Results confirm the existence of a predominantly alongshore current off the Tsitsikamma coast. At Middelbank eastward flow was slightly dominant, with a percentage occurrence of 58% vs. 41% westward flow near the surface. The percentage eastward flow decreased with depth, with 41% vs. 58% westward flow near the seabed. At Thyspunt westward and eastward flow occurred at near equal percentages. but westward flow was slightly dominant throughout the water column. The alongshore current was strongest near the surface during eastward flow (maximum = 141 crn.s1: average = 27 crn.s '). while westward surface currents were weaker (maximum velocity = 78 cm.s1: average = 19 crn.s1). Current speed generally decreased with depth and opposing surface and bottom currents, associated with a thermal stratified water column, were occasionally recorded. The nearshore flow regime was characterised by frequent barotropic alongshore reversals that occurred year round. An increase in strong eastward episodes, and opposing surface and bottom currents during spring and summer months have implications for the dispersal of squid paralarvae during the summer and winter spawning seasons. In summer, the combination of strong eastward pulses in the current and upwelling at the capes favoured dispersal onto the midshelf of the Agulhas Bank. In winter, alongshore oscillations without the offshore displacement associated with upwelling. restricted offshore dispersal which caused surface particles to be retained inshore. Drifter trajectories show that both the eastward and westward nearshore current can link the inshore spawning grounds with the nursery grounds, offshore on the central Agulhas Bank; and that passive, neutrally buoyant material in the surface layer can reach the vicinity of the cold ridge in as little as eight days. The wind-driven processes of upwelling and coastal trapped waves (CTWs). and the influence of the greater shelf circulation are discussed as possible driving forces of variability in the currents off the Tsitsikamma coast. The occurrence of coastal trapped waves during thermal stratification appears to drive the jet-like, eastward pulses in the current. and results suggest that the propagation of CTWs may regulate and even enhance upwelling and downwelling along the Tsitsikamma coast.

A idade e crescimento da lula Doryteuthis plei da região do litoral norte do Estado de São Paulo é descrita com base em 424 exemplares entre 1,58 a 267 mm de comprimento de manto (ML). Os estatólitos foram utilizados como ferramenta de análise de idade, bem como foi realizado um estudo ontogenético de sua morfometria e morfologia. Com o objetivo de analisar e aprimorar a curva e a taxa de crescimento de D. plei, o presente estudo deu ênfase aos indivíduos em estágios iniciais do ciclo de vida. O formato dos estatólitos foi descrito e demonstrou semelhança à de outros loliginídeos, porém com características particulares, suficientes para a identificação da espécie. Houve relação entre ML e o comprimento dos estatólitos (SL), obtido pelo modelo de ajuste logarítmico. A idade dos exemplares amostrados foi estimada e com isto foi possível obter a curva de crescimento (relação idade e ML) da população em estudo, a qual foi ajustada pelo modelo logístico. O mesmo modelo de ajuste houve para os machos, porém para as fêmeas e para os juvenis, o melhor modelo foi o Gompertz. A longevidade da espécie no local de estudo foi estimada em aproximadamente oito meses. A taxa de crescimento e suas variações conforme as estações do ano foram estimadas. Foram evidenciados valores sendo em mm/dia quando em estádio imaturos em relação aos adultos e decrécimo acelerado após atingir 60 mm ML. Foram observadas diferenças da taxa de crescimento entre os sexos quando os exemplares atingem 150 mm de ML. Espécimes nascidos no inverno apresentaram maiores taxas de crescimento em relação aos nascidos em outras estações do ano. Através do retro-cálculo da idade, foi observado que durante todo o ano ocorrem nascimentos de D. plei, em maior frequência no primeiro semestre. É possível estimar a idade de D. plei tendo apenas as medidas de SL ou comprimento dos domos, sendo que para cada relação, o ajuste obtido foi o logarítmico. Os parâmetros de crescimento apresentados no presente estudo oferecem recursos para estudos de avaliação do estoque pesqueiro e biologia populacional. / Age and growth of the squid Doryteuthis plei from the northern shelf off São Paulo are described based on 424 specimens from 1.58 to 267 mm mantle length (ML). Statoliths were used as microstructures for aging, and an ontogenetic study of their morphological and morphometric was performed. The present study aimed to analyze and improve the growth curve and growth rate estimate of individuals of D. plei, emphasizing those in early stages of life cycle. The shape of statoliths was described and demonstrated similarity other loliginids, with particular characteristics sufficient to identify the species. There was a relationship between ML and statoliths length (SL) by the logarithmic model. The age of sampled specimens was estimated and it was possible to obtain the growth curve (relationship between age and ML) of the population in study, was better fitted by the logistic model. The same adjustment was found for males, but for females and juveniles, the Gompertz model was best suitable. The longevity of the species from place of study was estimated at approximately eight months. The growth rate and its variations were estimated according to the seasons, which evidenced higher values in mm/day in immature stage when compared to adults. In addition, individuals after reaching 60 mm ML accelerated a decrease in growth rate. Differences in growth rate between sexes were found after specimens reach 150 mm ML. Specimens born in winter had higher growth rates when compared to those born in other seasons. Through retro-calculation of age, it was observed that births of D. plei occur throughout the year, but most frequently in the first half. The study enables the age estimate of D. plei having only measures of SL or length of the statolith\'s domes. Growth parameters obtained provide information useful for stock assessment and population biology.

Thesis (M.Sc.) -- Memorial University of Newfoundland, 1987. / Typescript. Bibliography: leaves 56-64. Also available online.

A idade e crescimento da lula Doryteuthis plei da região do litoral norte do Estado de São Paulo é descrita com base em 424 exemplares entre 1,58 a 267 mm de comprimento de manto (ML). Os estatólitos foram utilizados como ferramenta de análise de idade, bem como foi realizado um estudo ontogenético de sua morfometria e morfologia. Com o objetivo de analisar e aprimorar a curva e a taxa de crescimento de D. plei, o presente estudo deu ênfase aos indivíduos em estágios iniciais do ciclo de vida. O formato dos estatólitos foi descrito e demonstrou semelhança à de outros loliginídeos, porém com características particulares, suficientes para a identificação da espécie. Houve relação entre ML e o comprimento dos estatólitos (SL), obtido pelo modelo de ajuste logarítmico. A idade dos exemplares amostrados foi estimada e com isto foi possível obter a curva de crescimento (relação idade e ML) da população em estudo, a qual foi ajustada pelo modelo logístico. O mesmo modelo de ajuste houve para os machos, porém para as fêmeas e para os juvenis, o melhor modelo foi o Gompertz. A longevidade da espécie no local de estudo foi estimada em aproximadamente oito meses. A taxa de crescimento e suas variações conforme as estações do ano foram estimadas. Foram evidenciados valores sendo em mm/dia quando em estádio imaturos em relação aos adultos e decrécimo acelerado após atingir 60 mm ML. Foram observadas diferenças da taxa de crescimento entre os sexos quando os exemplares atingem 150 mm de ML. Espécimes nascidos no inverno apresentaram maiores taxas de crescimento em relação aos nascidos em outras estações do ano. Através do retro-cálculo da idade, foi observado que durante todo o ano ocorrem nascimentos de D. plei, em maior frequência no primeiro semestre. É possível estimar a idade de D. plei tendo apenas as medidas de SL ou comprimento dos domos, sendo que para cada relação, o ajuste obtido foi o logarítmico. Os parâmetros de crescimento apresentados no presente estudo oferecem recursos para estudos de avaliação do estoque pesqueiro e biologia populacional. / Age and growth of the squid Doryteuthis plei from the northern shelf off São Paulo are described based on 424 specimens from 1.58 to 267 mm mantle length (ML). Statoliths were used as microstructures for aging, and an ontogenetic study of their morphological and morphometric was performed. The present study aimed to analyze and improve the growth curve and growth rate estimate of individuals of D. plei, emphasizing those in early stages of life cycle. The shape of statoliths was described and demonstrated similarity other loliginids, with particular characteristics sufficient to identify the species. There was a relationship between ML and statoliths length (SL) by the logarithmic model. The age of sampled specimens was estimated and it was possible to obtain the growth curve (relationship between age and ML) of the population in study, was better fitted by the logistic model. The same adjustment was found for males, but for females and juveniles, the Gompertz model was best suitable. The longevity of the species from place of study was estimated at approximately eight months. The growth rate and its variations were estimated according to the seasons, which evidenced higher values in mm/day in immature stage when compared to adults. In addition, individuals after reaching 60 mm ML accelerated a decrease in growth rate. Differences in growth rate between sexes were found after specimens reach 150 mm ML. Specimens born in winter had higher growth rates when compared to those born in other seasons. Through retro-calculation of age, it was observed that births of D. plei occur throughout the year, but most frequently in the first half. The study enables the age estimate of D. plei having only measures of SL or length of the statolith\'s domes. Growth parameters obtained provide information useful for stock assessment and population biology.

The objective of this thesis is to analyse the management and redistribution policies implemented in the South African squid industry. This is done within the broader context of fisheries policies that have been implemented within the South African fishing industry as the squid industry has developed. The study therefore has an institutional basis, which reviews the development of institutional mechanisms as they have evolved to deal fisheries management problems. These mechanisms (which can either be formal or informal) consist of committees, laws and constitutions that have developed as society has progressed. Probably the most prominent of these, in terms of current fisheries policy, is the Marine Living Resources Act (MLRA) of 1998. The broad policy prescription of the MLRA basically advocates the sustainable utilisation of marine resources while outlining the need to restructure the fishing industry to address historical imbalances and to achieve equity. It is this broad objective that this thesis applies to the squid fishery. The primary means of achieving the above objective, within the squid industry, has been through the reallocation of permit rights. These rights also provide the primary means by which effort is managed. A disruption in the rights allocation process therefore has implications for resource management as well. Permits rights can be described as a form of use right or propertY right. These rights are structured according to their operational-level characteristics, or rules. Changing these rules can thus affect the efficiency or flexibility of a rights based system. This is important because initial reallocation of rights, by the Department of Environmental Affairs and Tourism (DEAT), was based on an incomplete set of rights. This partly led to the failure of early redistribution attempts resulting in a "paper permit" market. Nevertheless, this thesis argues that redistribution attempts were based on ill-defined criteria that contributed to the failure described above. In addition to this the method through which redistribution was attempted is also questionable. This can be described as a weak redistribution strategy that did not account for all equity criteria (i.e. factors like capital ownership, employment or relative income levels). This thesis thus recommends, among other things, that an incentive based rights system be adopted and that the design of this system correctly caters of the operational-level rules mentioned above. In addition to this a strong redistribution, based on fishing capital, ownership, income and the transfer of skills, should be implemented. / KMBT_363 / Adobe Acrobat 9.54 Paper Capture Plug-in

No / A system consisting of two Josephson qubits coupled through a quantum monochromatic electromagnetic field mode of a resonant tank circuit is studied. It is shown that for certain values of the parameters, it can be used as an entangling gate, which entangles the two qubits whilst the electromagnetic field remains disentangled. The gate operates with decent fidelity to a gate and could form the basis for initial experimental investigations of coupled superconducting qubits.

Superconducting Quantum Interference Devices (SQUIDs) are currently being used as flux qubits and read-out detectors in a variety of solid-state quantum computer architectures. The main limitation of SQUID qubits is that they have a coherence time of the order of 10 us, due to the presence of intrinsic flux noise that is not yet fully understood. The origin of flux noise is currently believed to be related to spin impurities present in the materials and interfaces that form the device. Here we present a novel numerical method that enables calculations of the flux produced by spin impurities even when they are located quite close to the SQUID wire. We show that the SQUID will be particularly sensitive to spins located at its wire edges, generating flux shifts of up to 4 nano flux quanta, much higher than previous calculations based on the software package FastHenry. This shows that spin impurities in a particular region along the wire's surface play a much more important role in producing flux noise than other spin impurities located elsewhere in the device. / Graduate / 0611 / 0607 / 0753 / laforest@uvic.ca

No / Vortices circulating in a ring made from a Josephson array in the insulating phase are studied. The ring contains a `dual Josephson junction' through which the vortices tunnel. External non-classical microwaves are coupled to the device. The time evolution of this two-mode fully quantum mechanical system is studied, taking into account the dissipation in the system. The effect of the quantum statistics of the photons on the quantum statistics of the vortices is discussed. Entropic calculations quantify the entanglement between the two systems. Quantum phenomena in the system are also studied through Wigner functions. After a certain time (which depends on the dissipation parameters) these quantum phenomena are destroyed due to dissipation.

While magnesium diboride (MgB2) was first synthesized in the 1950s, MgB2’s superconductive properties were not discovered until 2001. It has the highest superconducting transition temperature of all the metallic superconductors at ~39 K at atmospheric pressure. MgB2 is also unique in that it has a two superconductive gaps, a pi gap at 2 meV and a sigma gap at 7.1 meV. There are a theoretical models discussing the inter- and intra- gap scattering of the superconductivity of MgB2 and the Josephson transport of MgB2 Josephson Junctions. The focus of this work is to further the study of all-MgB2 Josephson junctions and quantum interference device technology. This work discusses the transport in all-MgB2 Josephson junctions and designing, fabricating, and measuring multi-junction devices. The junctions studied include all-MgB2 sandwich-type Josephson junctions (one with TiB2 normal conducting barrier and another with an MgO insulating barrier). The junction MgB2 films were deposited by hyprid physical-vapor deposition and the junction barrier were deposited by sputtering. The junctions were patterned and etched with UV photolithography and argon ion milling. With the TiB2 barrier we studied Josephson transport by the proximity effect. With these junctions, we also observed complete suppression of the critical current by an applied magnetic field showing for the first time a leakage free barrier in an all-MgB2 Josephson junction with a single ultrathin barrier. We also studied junctions utilizing MgO barrier deposited by reactive sputtering which gave a larger characteristic voltage of 1-3 mV compared to TiB2 barriers. By connecting several SQUIDs with varying loop areas we developed of two types of superconducting quantum interference filters (SQIFs). The first SQIF designed with 21 SQUIDs connected in parallel and the SQUID loops are sensitive to magnetic fields applied parallel to the substrate. The SQUID loop areas were designed to vary in such a way that the voltage modulation gave a unique peak corresponding to the absolute value of the applied magnetic field. The SQIF shows an antipeak height of 0.25 mV with a transfer function of 16 V/T at 3 K. The lowest noise measured for this SQIF is 110 pT/Hz1/2. The second SQIF is designed with 17 SQUIDs in parallel and the SQUID loops are sensitive to magnetic field perpendicular to the substrate. This SQIF has shown improved voltage modulation with a peak height of 1 mV and a transfer function of 7800 V/T. The noise sensitivity was measured at 70 pT/Hz1/2. The sensitivity of the SQIF shows MgB2 potential superconductor to improve performance of current superconductive electronics. Utilizing known all-MgB2 junctions and SQUID parameters two rapid single flux quantum (RSFQ) circuits were designed and tested. A toggle flip flop (TFF) operating as a frequency divider was developed. The TFF design consisted of a Josephson transmission line, a splitter, and an interferometer (a DC SQUID). The TFF utilized an improved designed, compared to previous all-MgB2 TFFs, and showed operation up to 335 GHz at 7 K and operation up to 30 K. A low frequency set-reset flip flop (SRFF) was also developed to demonstrate RSFQ digital logic. The SRFF design includes a DC-SFQ converter, a Josephson transmission line, and an inductively coupled readout SQUID. The SRFF demonstrates proper digital logic by toggling between a high and low voltage state with a sequential set and reset input. While these developed devices are not close to the potential that MgB2 allows, they do show the promise MgB2 based devices have in making more sensitive and faster superconductive logic devices. / Physics

Les SQUID (Superconducting QUantum Interference Device), à haute température critique, permettent la réalisation de magnétomètres directionnels à haute sensibilité, pour des fréquences allant du continu à plusieurs centaines de kHz. Les seuils de détection atteints en chambre blindée autorisent la caractérisation fine du biomagnétisme, dont celui du muscle cardiaque. L'objectif de cette thèse était de réaliser un magnétomètre portable, opérant la détection des signaux cardiaques en milieu magnétiquement non-blindé. La modélisation du signal magnétique cardiaque par un moment magnétique variable permet de montrer qu'une mesure optimale de ce champ peut être réduite à celle de sa composante normale au plan d'étude. Nous montrons également qu'une résolution de $100\,\mathrm(fT)/\sqrt(\mathrm(Hz))$ dans une bande passante de 100 Hz est nécessaire à sa caractérisation. Cependant, de nombreuses sources magnétiques contrarient toutes mesures sans blindage. Ces sources parasites, que nous avons analysées, peuvent être discriminées par leur évolution spatiale. Un sytème gradiométrique permet alors d'extraire le signal magnétique cardiaque en réalisant un filtrage spatial. Un tel dispositif, mis en oeuvre avec deux flux-gates et associé à un processeur de signal numérique (DSP), permet la mise en évidence des pics magnétiques du signal cardiaque et montre l'utilité et la souplesse du traitement numérique en temps réel pour notre application, y compris en milieu ouvert. Un magnétomètre à SQUID dc refroidi par un système cryogénique portable, du type tube à gaz pulsé, s'est révélé inadapté à la magnéto-cardiographie, le bruit lié à ce cryogénérateur pertubant trop largement les mesures dans la bande passante utile. Plusieurs systèmes gradiométriques à SQUID, refroidis par azote liquide, ont été mis en oeuvre. Le signal magnétique cardiaque a été mesuré sans blindage. Des techniques de réductions du bruit à basse fréquence du capteur permettront une meilleure caractérisation du signal cardiaque.