EE 4BI6 Electrical Engineering Biomedical Capstones

Chemical order in the Heusler alloys nickel(2) manganese(x) vanadium(1-x) tin by neutron diffraction

Luc Martin — Tue, 29 Mar 2011 07:48:59 PDT

The chemical ordering in samples of Heusler alloys of the series Ni₂MnxV₁-xSn, where x stands for 1.0, 0.8, and 0.6, has been measured by neutron diffraction. Measurements were performed at room temperature. The samples were long thing single crystals with cross-section less than 1 mm. The samples had been cut by spark erosion from large single crystal boules. Extinction was still present. The data were fitted with a nuclear structure factor, allowing for chemical disorder, based on a model of the crystal structure. They highly order in the L2₁ type crystal structure. Slight Mn, V←→Ni disorder was sufficient to explain the data. For x=1.0, (3.5 ± 1.2) at % disorder between Mn-V and Ni atoms was necessary to obtain the best fit. For x=0.8 the best fit was obtained with no disorder. Disorder was (2.8 ± 0.9) at % between Mn-V and Ni atoms for the x=0.6 sample. No evidence of any other type of disorder was found.

Investigations into the possible role of N-acetylserotonin as a neurotransmitter

Aldis Victor Porietis — Tue, 29 Mar 2011 07:17:53 PDT

A possible role for N-acetylserotonin (NAS) as a central nervous system neurotransmitter was investigated. Of the generally accepted criteria which are used to define transmitter function, those of localization and physiologic effect were pursued. Various immunohistochemical techniques were used to show the hippocampal distribution of NAS. This distribution was found to be distinctly different from that of melatonin and that reported for serotonin. NAS was located in sub-micron sized structures immediately adjacent to the hippocampal pyramidal cells in areas CA1 and CA3. There was also evidence for cells containing substantial quantities of NAS in the CA4/dentate region. Some fibres could also be identified here. The presence of NAS in the hippocampus of the rat was confirmed by gas chromatography-mass spectrometry (GCMS). Attempts to identify an extra-hippocampal source for the NAS found in hippocampus by use of lesions did not provide evidence that hippocampal NAS is dependent on an intact projection from brainstem via the fimbria-fornix pathway. A study using the 5HT synthesis blocker, p-chlorophenylalanine, showed that hippocampal NAS content can be reduced by this drug, as measured by GCMS. Immunohistology was further used to identify a population of cells which might be expected to respond to NAS, those being the pyramidal cells of the hippocampus. In the hippocampal slice preparation, NAS and 5HT were equally potent in inhibiting glutamate-induced cellular activity, as measured extracellularily. Melatonin could not affect the firing rate of the pyramidal cells. It is concluded that this line of research may be useful in further defining the functional role of NAS in the CNS of rat.

Karst development and groundwater flow in the Quatsino FM. northern Vancouver Island

William Robert Paul Mills — Tue, 29 Mar 2011 07:04:03 PDT

This study attempts to determine the nature of karst developed in uplifted and intruded carbonate strata on northern Vancouver Island, Canada. Hydrochemical analyses are employed to determine the potential of the solution process imposed by geochemical constraints, and to investigate the extent to which hydrochemical character can be used to inerpret the nature of groundwater flow and the spatial distribution of solution in the karst. Examination of landscape form, particularly in cave passages, is employed to further understanding of the physical constraints on groundwater flow and cave development, and to interpret the historical record preserved there.

Books of spiritual guidance for children during the Puritan-Anglican controversy in the seventeenth century

Alice Zorn — Tue, 29 Mar 2011 06:39:11 PDT

In this paper I have discussed books of spiritual guidance for children within their historical context. The authors were writing during the time of conflict between the Anglicans and Puritans in the mid-seventeenth century. Their most obvious aim is to secure converts for their particular denominational cause. I attempt to uncover the denominational ideals, as well as the more general ideals concerning man, his world, and his relation to others. These books have not previously been examined by scholars, nor by historians of children's books in this way. The books and authors are: A little book for little children (1660) by Thomas White, A choice manual (1669) by Jeremy Taylor, A token for children (1672) by James Janeway, and Of education (1687) by Obadiah Walker. The books can be found in their original state in the Osborne Room of the Toronto Metropolitan Library.

The relationship between soil temperature and the plant cover of a lichen dominated raised beach system in subarctic Ontario

Cameron A. McGregor — Wed, 23 Mar 2011 11:14:36 PDT

Sqil temperature measurements were made under different plant covers to the base of the rooting zone of the raised beaches of the Hudson Bay coastal tundra region to determine the relationship between plant cover and the soil thermal regime. Two methods of description were used for quantitative comparison of temperature; 1) linear regression of daily averages and Fourier amplitudes over the field season to dermine near-surface differences in energy entering the soil under different plant covers and 2) a soil temperature model was constructed to separate physical influences over soil temperature from that of the plant cover. It was found that plant density had some control over the amount of energy transferred to the soil, causing a maximum difference of 7℃ in the upper layers between different plant covers. From the modelling process it was found that the humus layer had essentially no effect in the transfer of energy throughout the rooting zone during the summer months and it was postulated that the observed difference in soil temperature between sites of different plant cover was due to a differential rate of spring thaw caused by the different thickness of humus between sites.

On the compaction of metal powders with particular reference to densification hardening

Abd El Razek Youssef Kandeil — Tue, 22 Mar 2011 18:00:10 PDT

The purpose of this work was to examine the process of isostatic compaction of metal powders and the related phenomenon of densification hardening.

The relationships between density, hardness and compacting pressure, for different commercial powders, have been obtained. Data resulting from the experimental study of isostatic compaction was applied to tests conducted on die compacts, enabling the density and pressure distributions to be examined by simple hardness measurements. The compacts were produced in a range of compacting dies, designed especially for this purpose.

Results of density determination and metallographic examination of a series atomized aluminum, copper, lead and reduced iron powder compacts are presented. From these results it is concluded that extensive plastic deformation occurs even during the initial stage of compaction.

It has been shown that density and hardness are uniform within compacts produced by the isotatic method, while the die compacts showed remarkable variation of hardness and density within the samples. The results indicate the higher efficiency of the isostatic compaction method as compared to the die method.

A method for isostatic pressure measuring and recording, utilizing the expansion of the pressure vessel, is described.

Guerilla struggle in Africa : a two-case study in Mozambique and Rhodesia

Harendra Gulabh — Thu, 17 Mar 2011 12:32:30 PDT

It is the intention of this study to explore the hypothesis that a revolutionary peasant consciousness forms a quintessential ingredient in the complex of forces that culminate in a successful guerilla struggle. Beyond this, it will be demonstrated that the success of the struggle in Mozambique is a product of a development of an ideological clarity during the course of a struggle where the ruling class was in decay and thus lacked the indigenous capacity to forge a sustained, cohesive defense against the revolutionary movement. In Rhodesia on the oher hand, while many of the objective conditions have contributed to the development of guerilla struggle, as in Mozambique, nevertheless the presence of a well-entrenched, indigenous, while bourgeoisie with sole domination of state power has been a great barrier to the protracted struggle. Consequently, the greater difficulties inherent in this have minimized guerilla gains. This has resulted in sectarianism and a diminution of peasant consciousness with an overall deleterious impact on the Zimbabwe struggle as a whole.

A model for investigating traffic assignment and control in a freeway corridor

Said M Easa — Thu, 17 Mar 2011 12:22:45 PDT

A procedure for predicting traffic behaviour in a freeway corridor is developed. Traffic demand can vary over time and is assigned to the freeway and surrounding network subject to the hypothesis that individual travellers will minimize their travel time. The impact of queueing time on minimum paths is included by utilizing a traffic diversion model. The model is capable of diverting all, some, or none of the traffic from a particulat queueing path, and can therefore be used to investigate the effects of freeway entrance ramp control upon the adjacent road system.

A computer program was developed and incorporates several other new features for network traffic flow assignment. These include turning volume calculations without the requirement of separate turning links, the ability to impose turning movement prohibitions at critical locations, and a procedure for identifying illogical paths.

A new minimum path algorithm was developed to ensure that illogical paths were not used, and prelimiary tests indicate that it is more computationally efficient than previous versions. Due to such improvements in the assignment procedure, link-node representation was simplified and use of the model requires considerably less coding effort as well.

The new model was fully tested using a relatively large freeway corridor network, and results show that it can be useful for evaluating ramp control strategies and predicting the resulting flows and queues corresponding to any desired case of diversion.

The analysis application and manufacture of air structures with reference to Canada

Stuart Critchley — Thu, 17 Mar 2011 12:06:51 PDT

The development and analysis of physical characteristics pertaining to the construction, operation and maintenance of air structure systems is presented, with particular emphasis being given to Canadian applications. A design methodology appropriate to the design of air structures is introduced, and successfully utilised in the production of a structure installed in Nova scotia in 1973. Further comparative examples are presented to illustrate the versatility of air supported structures with reference to future requirements.

Transfinite Cardinal Arithmetic

Kathryn Anne Murphy — Thu, 17 Mar 2011 11:54:22 PDT