identifier: Qi, Chong Qing <https://research.library.mun.ca/view/creator_az/Qi=3AChong_Qing=3A=3A.html>   (1993) Application of immunomagnetism for antigen preparation and cell selection in the creation of hybridomas.  Masters thesis, Memorial University of Newfoundland.

abstract: As part of a larger program to make monoclonal antibodies to HLA-DP polymorphisms, the possibility of using immunomagnetism to replace some cumbersome procedures in hybridoma creation was investigated. In the first part of this study, metallic beads were coated with anti-DP capture antibody and then were used for immune absorption of DP molecules from cell lysates. The absorbed molecules were identified with the help of a fluorescent anti-DP antibody and flow cytometry. Optimum conditions for absorption of DP molecules onto beads were worked out. In the second part, the immunogenic properties of the purified DP molecules were tested, in which metallic beads coupled with absorbed molecules were injected into mice to provoke an immune response. Serum antibody corresponding to three different antigen doses was determined and showed that the strong antibody response was correlated with the large dose of antigen. The influence of beryllium sulphate and complete Freund's adjuvant on these antibody responses was compared. In the final part of the study, immune spleen cells were sorted by using goat anti-mouse IgG coated metallic beads and/or antigen coupled beads. Following magnetic separation the selected spleen cells were fused with SP2/o myeloma cells without the detachment of the beads, using a centrifugal-electrofusion technique. Hybridomas which secreted antibodies were examined for their specificity to DP polymorphisms. The frequency of positive hybridomas, in fusions of pre-selected cells, was compared with that of the fusion of unsorted cells (prior to selection) and with that of the remainder of the cells left behind after a sort. Once a variety of tissue culture problems had been resolved, there was preliminary evidence suggesting that pre-fusion selection of antigen-specific cells can be a helpful and time-saving procedure.


identifier: Fagan, Donna M. <https://research.library.mun.ca/view/creator_az/Fagan=3ADonna_M=2E=3A=3A.html>   (2001) Rosacea : a review of family history and community of origin.  Masters thesis, Memorial University of Newfoundland.

type: Thesis NonPeerReviewed

abstract: This descriptive study was conducted utilizing a cohort of diagnosed rosacea patients from a group dermatologists' clinic serving a population in Eastern Newfoundland. The etiology of rosacea is unknown, therefore, this study was conducted to answer two primary questions: (1) is there a family history of rosacea and (2) can rosacea be traced to a particular ancestral community of origin for the population under study? A literature review reveals that little has been documented regarding family history and ethnicity. Additional data was concurrently collected including basic demographics, frequency and severity of triggers, exposure to sun, quality of life and the occurrence of other skin conditions. -- One hundred and fifty-two patients with rosacea were drawn from new or returning patients to the dermatology practice during the spring, summer and fall of 2000. As each patient checked in with the receptionist s/he was asked to participate in this research by completing a self-administered 106 question survey. -- Results revealed a strong family history of rosacea in 67% of the cases. There emerged a community or region of origin in a particular area of the catchment area. The origins of the majority of the settlers to Conception Bay North and Trinity Bay South are from the southwest area of England. The population is of fair skin with dark and light brown hair and blue eyes. The average age of diagnosis is in the fifth decade of life. Occupational work of the respondent group was conducted primarily indoors, sun screen use was absent or insignificant in childhood and adolescence. The occurrence of other skin conditions was present in one quarter of the cases. The frequency and severity of triggers are comparable to previously reported data. -- The results point to a strong familial relationship, leading to the conclusion that genetic etiology is probable. This information together with knowledge of ancestral community of origin provides an area to begin genetic research.


identifier: Hasan, Md. Tariqul <https://research.library.mun.ca/view/creator_az/Hasan=3AMd=2E_Tariqul=3A=3A.html>   (2001) Analyzing longitudinally correlated failure time data : a generalized estimating equation approach.  Masters thesis, Memorial University of Newfoundland.

abstract: Multivariate correlated failure time data can be classified into two different groups: structural failure time data and longitudinal failure time data. As compared to the analysis of the structural failure time data, the analysis of longitudinal failure time data has however proven to be difficult, perhaps because of the difficulty in the modeling the true longitudinal correlation structures. In the present thesis, following certain longitudinal correlation models, recently developed for discrete data, we develop three longitudinal correlation models for exponential failure times to deal with such multivariate longitudinal data. Under these three models, we construct the co-variance structures of the martingales of the failure times for both uncensored and censored cases, and use them to develop a generalized estimating equation approach to estimate the parameters of main interest, namely, the hazard ratio parameters. The efficiency loss due to misspecification of the correlation structure is studied for both uncensored and censored cases. As the proposed generalized estimating equation approach use either the underlying true correlation structure for both uncensored and censored cases or a suitable robust correlation structure for the uncensored case, the methodology yields consistent as well as efficient estimators for the hazard ratio parameters. We apply the methodology to a numerical example.


identifier: Gilbert, William <https://research.library.mun.ca/view/creator_az/Gilbert=3AWilliam=3A=3A.html>   (2002) Russell's Point (CiAj-1) : a Little Passage/Beothuk site at the bottom of Trinity Bay.  Masters thesis, Memorial University of Newfoundland.

abstract: Russell's Point (CiAj-1) is a Little Passage/Beothuk site located on the western side of Dildo Pond roughly 2.4 km (1 ½ miles) south of Dildo Arm at the bottom of Trinity Bay. It was found using information contained in John Guy's journal of his voyage into Trinity Bay in the fall of 1612 and is believed to be the site visited by him on October 26, 1612 and described by him in his journal. Between 1994 and 1997, twenty-six weeks were spent working at the site, 158 square metres were excavated, 23 major features were located, mapped and photographed and 1225 artifacts recovered. Excavation and subsequent analysis focused on determining how long the site had been utilized by the Beothuk and their ancestors, what role the site had played in the seasonal round of the Trinity Bay Beothuk, and what effect, if any, contact with Europeans had had on the material culture of the Trinity Bay Beothuk by the second decade of the seventeenth century. -- Analysis of the data indicates that the site was utilized by the Beothuk and their ancestors for roughly 650 years from circa A.D. 1000 to circa A.D. 1650 and that it probably served as a fall and winter base camp. The limited amount of European material recovered indicates that while the Beothuk at Russell's Point had adopted a certain amount of European material by the time the site was abandoned and had begun to modify iron, their material culture was still largely based on traditional materials and suggests that the adoption of European materials must have greatly accelerated in the second half of the seventeenth century after Russell's Point was abandoned.


identifier: Fanning, Augustus F. <https://research.library.mun.ca/view/creator_az/Fanning=3AAugustus_F=2E=3A=3A.html>   (1993) An analysis of wind-forced, seasonal transport variability at the Florida Straits using linear models of the North Atlantic.  Masters thesis, Memorial University of Newfoundland.

abstract: Two linear models of the North Atlantic, a linear barotropic model and a linear two-density layer model, are employed to investigate the effect of using different wind stress climatologies on the model-calculated transport. Particular emphasis is placed on the model-calculated response at the Florida Straits. The model domains extend from 10°S to 65°N and 100°W to 15°E at 1° x 1° resolution. The wind stress climatologies are those of da Silva et al.(1993a; hereafter DS), Hellerman and Rosenstein (1983; hereafter HR), Isemer and Hasse (1987; hereafter IH) and Trenberth et al. (1990; hereafter TR). Comparing the results at the Florida Straits, we find that for each climatology, the barotropic model shows maximum northward transport in the summer and minima in the fall and late winter, in general agreement with transport measurements from cable data (Larsen, 1992). However, the amplitude of the model response differs considerably between the climatologies. In the case of DS the range (maximum transport minus minimum transport) is 2.8 Sv; HR, 3.6 Sv; TR, 5.2 Sv and IH, 5.9 Sv, compared to a range of 4.6 ± 0.4 Sv derived from cable data. When the JEBAR (Joint Effect of Baroclinicity And Relief; Sarkisyan and Ivanov, 1971) forced transport is also considered, using the two-layer model, the amplitude of the model-calculated response changes slightly in each case, with ranges of 3.3Sv, 3.9Sv, 5.8Sv and 6.1Sv for each of DS, HR, TR, and IH respectively. -- We have also conducted experiments using a 1/3° x 1/3° version of the model applied to the region extending from 5°N to 42°N, and 100°W to 70°W. The Bahama/Antilles Island Arc are resolved in this model. Transport through the boundary at 70°W is specified from the 1° x 1° calculations referred to above. The details of the model-calculated response are particularity sensitive to the precise choice of grid point used to represent the offshore boundary of the Florida Straits. If we choose the Grand Bahama Islands, the cases with transport specified on the eastern boundary yield ranges of 1.3Sr, 2.8Sr, 3.0Sr and 3.1Sr for each of DS, HR, TR, and IH respectively. If instead, we choose a region between the Grand Bahama Island, and Andrew Island (the Providence Channel area) the 1/3° x 1/3° model calculated results agree quite well with our 1° x 1° results. This is a consequence of the fact that even at 1/3° x 1/3° resolution, we still do not properly resolve the Florida Straits. In fact, in the model the Straits are much too shallow (roughly half the depth of the true Florida Straits), and hence, does not receive as much information along ƒ/H contours as in the 1° x 1° case, or as the grid-point in the vicinity of the Providence Channel. -- The increased range in the IH case compared to HR in our 1° x 1° case is in general agreement with the finding of Böning el al.(1991b) using the Kiel version of the model that forms the WOCE Community Modelling Effort. However, whereas Böning et al. claim that winds north of 35°N  have little influence on the seasonal response of their model at the Florida Straits, we find that winds north of 35°N play an important role in our model. The reason for the behaviour of the Community Model is not clear but may be associated with advection by the western boundary current. In our model, to show the importance of forcing by the meridional component of the wind, although forcing through the zonal component also plays some role in explaining the differences between the cases run under the different climatologies. We also show the importance of forcing associated with the meridional component of the wind along the continental slope region north of the Straits.


identifier: Butler, Trevor Roy <https://research.library.mun.ca/view/creator_az/Butler=3ATrevor_Roy=3A=3A.html>   (2002) An analysis of stiffened plating subject to extreme ice loads.  Masters thesis, Memorial University of Newfoundland.

abstract: Discovery of large oil and natural gas deposits in arctic and subarctic regions of  Canada has led to vastly increased offshore activity in these areas. This activity has increased the exposure of marine structures to ice loads. The ability of designers to assess accurately the response to ice loading is essential for the efficient design of these structures. In arctic areas, structures regularly encounter various forms of ice such as level ice, pack ice and pressure ridges, which are composed of both first-and multi-year ice. In contrast, in subarctic regions (for example, off the coast of Newfoundland), structures have much less frequent encounters with first-year pack ice and icebergs. In these situations, inadequate consideration of ice loads could make the risk level of operations in ice unacceptably high. -- This study is focussed on gaining an understanding of stiffened plating behaviour when subject to ice loads. Literature in three main areas was studied: ice failure processes during ice-structure interaction, definition of stiffened plate failure modes (or limit states) and reliability analysis, which incorporates these limit states into a probabilistic framework for design. The estimation of the response of a stiffened plate to extreme loads is greatly facilitated through an experimental analysis. To this end, a small-scale stiffened plate panel, subject to a lateral patch load, was tested to failure in the Structures Laboratory at Memorial University of Newfoundland. The patch loading is an idealisation of the two possible ice interaction scenarios in the waters off Newfoundland. The first is when level ice (or pack ice) acts upon, say, a ship's side shell. The second is the impact of a growler or bergy bit on a ship or platform leg. A detailed description of the physical model is given, along with results obtained. The use of finite element (FE) modelling techniques has greatly improved the study of complicated loading scenarios and structural response. A comparison of experimental results with those from a finite element analysis was carried out to assess the accuracy of the developed model. Once verified, the FE model is used in a sensitivity analysis of stiffener size to determine the effect size has on the ultimate strength of a stiffened plate. This will help understand the role the stiffeners play in structural design. Finally, a sample analysis is conducted to show how information regarding stiffened plate behaviour is implemented in reliability-based design.


identifier: Thornhill, Eric <https://research.library.mun.ca/view/creator_az/Thornhill=3AEric=3A=3A.html>   (2002) Application of a general CFD code to planning craft performance.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract: Performance prediction is an important part of vessel design. Common methods for predicting planing hull performance include the use of empirical equations and model testing. Empirical equations are often only applicable to similar hull types over a small range of parameters, while model testing is often prohibitively expensive, particularly for small craft. Ever increasing computer power is making the use of computational fluid dynamics (CFD) as a performance prediction tool a practical alternative. This work presents the results of a study involving CFD to evaluate the performance of a high-speed planing vessel moving at steady speed through calm water. --  After a review of the state-of-the-art in CFD methods, it was decided that an unstructured, multiphase, finite volume code employing the volume-of-fluid (VOF) method for free surface capturing would be best suited for the study. The use of a commercial CFD code was found to be the best alternative as they are publicly available, generally undergo extensive validation, have a wide user-base, and receive periodic upgrades and improvements. The code chosen was Fluent (v5.3). --  Fluent could not, however, be used directly to simulate the behaviour of a planing vessel. The performance of high-speed craft is intimately linked to the orientation of the hull at speed, which cannot be known a priori. Planing hulls rise and change trim angle in response to the pressure field generated by the flow. In order to solve for these changes in hull position, the simulation method had to ensure that dynamic equilibrium was achieved in terms of lift and trimming moment. This was accomplished with an iterative scheme wherein the flow field was solved for discrete hull orientations that were then adjusted based on force and moment results until the conditions of equilibrium were met. --  The work began with a set of physical model experiments used to provide the baseline from which the numerical results would be evaluated. Three sets of simulations were then performed to evaluate the prediction method. The first set fixed the hull orientation to match those measured in the physical experiments. This enabled a direct comparison of the numerical results to the physical results. A second set of simulations was then performed where only the equilibrium condition of lift was satisfied; trim angles remained fixed at the experimental values. The last set of simulations solved for equilibrium in both lift and trimming moment and represent the results of predictions that would be produced without the benefit of physical experiments. -- It was found that the CFD simulations produced high hull pressure forces compared with the experimental results. In the first set of simulations, this meant high drag forces. When the model was permitted to move vertically (with a fixed trim angle) in the second set of simulations, the numerical model lifted higher in the water. This reduced the pressure drag results, but decreased the wetted area and hence the frictional drag. During the last set of simulations, which permitted the model to trim and heave to achieve dynamic equilibrium, trim angle and sinkage were found to decrease relative to the previous simulation set. As a result, pressure drag was found to decrease, but frictional drag predictions improved. Values for total resistance were found to be low when compared with experimental results. The under predicted resistance results from the second and third set of simulations were a direct consequence of the over predicted hull pressures identified during the first set of simulations. Despite these high pressure values, the results of the predictions still followed experimental trends, and the procedure for solving dynamic equilibrium was successful.


identifier: Sellars, Desmond <https://research.library.mun.ca/view/creator_az/Sellars=3ADesmond=3A=3A.html>   (1999) School discipline theory and practice : implications for policy development in an isolated, rural school setting.  Masters thesis, Memorial University of Newfoundland.

abstract: This thesis has no abstract.


identifier: Apostolovic, Nenad <https://research.library.mun.ca/view/creator_az/Apostolovic=3ANenad=3A=3A.html>   (2003) An innovative method for improvement of robotic simulation cycle time accuracy.  Masters thesis, Memorial University of Newfoundland.

abstract: Robotic simulations can be classified into two groups - ones provided by the robot manufacturers and the generic ones provided by the simulation software companies. Both types have advantages and disadvantages with respect to cost, accuracy, functionality and integration with other virtual manufacturing tools. -- Improvement of motion accuracy is one area of significant development of  generic robotic simulations. Upon completion of the RRS I (Realistic Robotic Simulation) project, it finally became possible to use original motion and kinematics algorithms, which minimized differences between the simulated motion and real motion. However, RRS I Specification has several serious drawbacks. Not many robot manufacturers provide modules, functionality is limited and the price is high. -- Presented material proposes a new method for improvement of simulation motion time accuracy. The method is based on the assumption about the existence of factors, whose influence on motion time of the real robot can be identified and incorporated through correction factors into the simulation motion model.


identifier: Mayo, Dennis Joseph <https://research.library.mun.ca/view/creator_az/Mayo=3ADennis_Joseph=3A=3A.html>   (1996) An in vitro study of α and β adrenoreceptors in melanosome differential aggregation and dispersion associated with cryptic patterning in winter flounder (Pleuronectes americanus).  Masters thesis, Memorial University of Newfoundland.

abstract: The remarkable cryptic patterning capability of flatfish gives rise to important questions about the regulatory processes which must be involved in the differential control of melanophores. Winter flounder, Pleuronectes americanus, possess three distinct pattern components on its dark upper (ocular) surface that are important for cryptic patterning. These are the white spot, general background and dark band components that display differential chromatic responsiveness which has been studied using electrophysiological and pharmacological methods in the current work. -- In vitro experiments with K⁺ rich aggregating fluid (AF) or noradrenaline and phentolamine demonstrate that α-adrenoceptors mediate melanosome aggregation. Studies examining the effects of increasing concentrations of prazosin and yohimbine on melanosome aggregation evoked by electrical stimulation indicate that both α₁- and α₂-adrenoceptors play a role in melanosome aggregation, but there is a predominance of the latter. Experiments with atenolol suggest that there may be some β-adrenoceptor synergism involved in pigment aggregation. -- Topical application of low concentrations of soproterenol and noradrenaline enhance rates of in vitro melanosome dispersion in balanced salt solution which could be depressed with propranolol and suggests β-adrenoceptor mediation. The subtype of this adrenoceptor appears to be most likely the β₂ conformation based on studies with terbutaline. Denervation of scale slips in 6-OH dopamine followed by incubation in a high concentration of isoproterenol and propranolol results in complete melanosome aggregation. Incubation of denervated scale slips in the same concentration of isoproterenol and phentolamine results in the blockade of pigment aggregation. -- This study shows that α- and β₂-adrenoceptors play roles in pigment aggregation and dispersion respectively and that the melanophore response that is initiated is dependent upon neurotransmitter concentration. High concentrations of noradrenaline or isoproterenol evoke melanosome aggregation via α-adrenoceptors while low concentrations induce melanosome dispersion via β₂-adrenoceptors.


identifier: Gauthier, Stéphane <https://research.library.mun.ca/view/creator_az/Gauthier=3ASt=E9phane=3A=3A.html>   (2001) Acoustic properties and shoaling behavior of Atlantic redfish (Sebastes spp.).  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract: Acoustic properties, shoaling behavior and diel vertical migration of Atlantic redfish (Sebastes spp.) were studied with the objective of enhancing the basis for acoustic assessment techniques. The acoustic target strength (TS) of redfish was measured using both ex situ and in situ methods. To conduct ex situ experiments, a technique was developed to maintain captive individuals alive for study in an experimental set-up using a split-beam echosounder. Techniques of in situ TS estimation were also studied in detail and approaches to minimize biases are proposed. Systematic bias in TS occurred above a certain density threshold. The measurement scale used to estimate density influenced the threshold level. Deep-tow dual beam and hull-mounted split beam systems were used to measure the TS of redfish at sea (in situ) under various environmental and biological conditions. After controlling for effects of thresholding, fish density, reverberation volume, range, and avoidance behavior, in situ and ex situ data did not differ and were pooled to obtain a TS-length model of TS = 20Log[length(cm)]-68.7. --  Redfish exhibited strong patterns of diel vertical migration and many diverse types of shoaling behavior at several spatial scales, both of which can affect acoustic and trawl survey results. During vertical migration. TS did not change significantly and it appears that redfish have an endogenous cycle for the control of swimbladder gas. Catch data indicated increased mean fish length with depth, while length standard deviation was highest in shallow areas. Pelagic schools of various size and density were most evident in spring and summer. The extent of vertical migration appeared to be limited by differential hydrostatic pressure and related to light condition and feeding. -- Acoustic-trawl experiments indicated that bottom trawl catches consistently underestimated redfish density. Acoustic assessments were biased downward during the day, because an increased proportion of fish occupied the near-bottom acoustic dead zone (DZ) and there was increased heterogeneity in distribution. This work suggests that the most accurate and least variable estimate of redfish abundance can be achieved using acoustics during the night, when fish are dispersed in the water column and most available to acoustic measurement.


identifier: Laurie, Brenda J.(Brenda Joyce) <https://research.library.mun.ca/view/creator_az/Laurie=3ABrenda_J=2E=28Brenda_Joyce=29=3A=3A.html>   (1981) Accounting for teacher effectiveness in reading instruction : demonstrating clear definite belief.  Masters thesis, Memorial University of Newfoundland.

abstract: The purpose of the study was to determine the effects of a hypothesized causal chain whereby certain antecedents affect mediating variables with subsequent consequences. In particular, it was hypothesized that reading teachers who demonstrated the presence of a clear definite belief system on an instructional approach would have significantly higher classroom reading achievement than others who didn't. Clear belief or clear goals ought to lead to corresponding behavior in the classroom and clarity, efficiency and persuasiveness in instruction. The linking of these chains of events would be crucial in determining teacher effectiveness. Reading research has been characterized by inconclusive results in determining effectiveness of various methods and programs. This study attempted to link the "professional" teacher with these methods with the intention of proving that the combination makes a significant difference. -- The sample consisted of 36 randomly selected Grade 2 classrooms. The teachers were interviewed and questioned on their strategies of instruction and were observed in the classrooms for approximately 20 sessions over a period of one school year. Students were tested in reading at the beginning and end of that school year. -- Analysis of interview responses revealed that teachers varied in their beliefs on an instructional approach to reading. Further analysis of their consistency in belief and behavior and their performance ratings revealed that their beliefs also varied in strength and credibility. The majority of teachers did not have clear definite beliefs on an instructional approach to reading. However, tests of significant difference between the reading achievement means of consistent teachers and inconsistent teachers proved positive. Similarly did tests between "clear definite belief" teachers and those outside that group prove highly significant differences. ANOVA's revealed no differences in reading achievement could be accounted for by the instructional method or by the belief held when each of these factors operates independently. -- Multiple regression analysis was conducted on reading gain for the effects of the linear combination of variables hypothesized. Twenty-five to thirty-four percent of the variance in residualized reading gain was accounted for by each of the paths operating singly. -- Some problems existed in the analysis due to the inaccuracies arising from the use of forced choice interview questions. This prevented the establishment of positive causal connections between belief, behavior, performance rating and subsequent reading achievement. However, using consistency and positive performance ratings as conditions of clear definite belief enabled this study to overcome the initial problems.


identifier: Xia, Huanliang <https://research.library.mun.ca/view/creator_az/Xia=3AHuanliang=3A=3A.html>   (1999) An analysis for braced excavations in clay.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract: This thesis studies braced excavations in clay with centrifuge tests and finite element analyses. -- Centrifuge experiments of 72 g are carried out to investigate earth pressures on the back of sheet piles, forces in the struts, the surface settlement and bottom heaving. The simulated depth of excavation is 11.5 m and the width is 17.3 m. The struts are applied before excavation for the convenience of the tests. Heavy liquid of sodium polytungstate (3Na₂WO₄.9WO₃.H₂O) is used to simulate the soil which would be excavated. The excavations are simulated by draining the liquid during the tests. -- The details of designing the model, preparing the soil, assembling the equipment and experimental procedures are described. Compression and triaxial tests are also carried out to obtain the mechanical parameters for the numerical analysis. -- A finite element analysis is carried out for the model and the results are compared with experimental data and established methods. The Cam-clay model is used for the soil. Eight node rectangular elements with pore pressures on the corners are used for the soil and block elements are used for the sheet piles. The results show that the finite element may predict most behaviour of the excavation. -- The finite element model is used to perform parametric studies where each layer of struts is applied after the soil of the corresponding layer is excavated. The effects of variation of the properties of soil, the stiffness of sheet piles and struts and the vertical distances between the struts are investigated.


identifier: Zhou, Yongxin <https://research.library.mun.ca/view/creator_az/Zhou=3AYongxin=3A=3A.html>   (1998) Alternative algebras and RA loops.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

title: Alternative algebras and RA loops

abstract: In the first part of this thesis, we study the relationships between three algebra structures: Cayley-Dickson algebras, RA loops and alternative loop algebras. -- Let R be a commutative associative ring with 1 and let A be an R-algebra with unity of characteristic different from 2. For any α, β and γ ∈ A, let A(α,β,γ) be the Cayley-Dickson algebra. We construct an RA loop L from each Cayley-Dickson algebra A(α,β,γ), called the induced RA loop. We show that any RA loop is a homomorphic image of some induced RA loop. After introducing the category of Cayley-Dickson algebras and the category of RA loops, we show that the two categories are equivalent. -- Using the induced RA loops, we show that any Cayley-Dickson algebra is a homomorphic image of an alternative loop algebra. Thus we give a new way of representing a Cayley-Dickson algebra. Furthermore, the homomorphism commutes with the norm and trace operations of the alternative loop algebra and the Cayley-Dickson algebra. The kernel of this homomorphism is completely determined. The prime radical and Jacobson radical of some Cayley-Dickson algebras are determined. A result of de Barros is generalized. The more general form of the homomorphism is studied. -- Necessary and sufficient conditions for an RA loop to be the Moufang circle loop of a quasiregular alternative algebra are given. The algebra structure of a finite alternative nilpotent ring with the Moufang circle loop being an RA loop is completely determined. -- In the second part of this thesis, the alternative rings of order p⁴ and p⁵ are completely determined, where p is a prime. This generalizes a result of A. T. Gainov. The two smallest alternative rings have order 2⁴ . For each prime number, there are fifteen alternative rings of order pn, n ≤ 5. The relationships between these fifteen rings are described. From these alternative algebras, a class of group-graded alternative algebras is derived.


identifier: Bass, Sarah J. <https://research.library.mun.ca/view/creator_az/Bass=3ASarah_J=2E=3A=3A.html>   (1995) Ambient noise in the surf zone.  Masters thesis, Memorial University of Newfoundland.

title: Ambient noise in the surf zone

abstract: Ambient noise in the surf zone was recorded using a broad-band hydrophone, located approximately one meter below the sea surface, in the frequency range 100 Hz to 5 kHz. The predominant source of this noise is from breaking waves. Analysis of simultaneous land-based video observations of the sea surface in the region of the hydrophone, along with wave height data, reveals qualitative correlation between wave-breaking events and the hydrophone signal. In energetic surf, the sounds appear to be generated locally. Sounds from distant breaking events are not detected probably due to the effects of bubble screening. The detection by the hydrophone of breaking waves in the immediate vicinity implies that ambient noise in heavy surf provides a means of studying individual breakers and is a useful measure of local breaking frequency.


identifier: Bettles, Stephen Paul <https://research.library.mun.ca/view/creator_az/Bettles=3AStephen_Paul=3A=3A.html>   (1997) Advancement of ovulation in yellowtail founder (Pleuronectes ferrugineus) using gonadotropic hormone-releasing hormone analogue (GnRHa).  Masters thesis, Memorial University of Newfoundland.

abstract: Yellowtail flounder (Pleuronectes ferrugineus) are being considered for aquacultural development and in order to maximize productivity within a hatchery, a thorough knowledge of the reproductive cycle and how it may be manipulated, must be attained. -- Ovarian biopsies, using polyethylene cannulae, were used to follow the annual oocyte growth pattern in yellowtail flounder. Vitellogenesis, as measured by an increase in both oocyte diameter and opacity, began in October-November, and progressively continued until the spawning season, between June and August The use of cannulae for ovarian biopsies in yellowtail flounder was validated by assessing homogeneity of oocyte sizes throughout the ovary, indicating that oocytes from the anterior ⅓ of the ovary were representative of the entire left and right ovaries. -- The capacity to advance the yellowtail flounder spawning season using gonadotropic hormone-releasing hormone analogue ([D-Ala⁶,Pro⁹-NHEt]GnRHa) was studied in maturing females by administering the hormone in three separate spawning trials, four months, two months and two weeks prior to the natural spawning season. From ovarian biopsies taken at time of treatment, it was found that the spawning response was dependant upon oocyte size reaching approximately 400μm before final egg maturation, and ovulation, could be induced. In addition, the response to GnRHa treatment was quicker, more uniform, and better synchronized closer to the natural spawning season, with 25%, 100% and 100% of the females spawning in each group, respectively, and the mean number of days to first ovulation being 25, 20, and 14 days, respectively. -- Egg quality was measured by morphological criteria of unfertilized eggs (viability rates or the percentage of potentially fertilizable eggs), fertilization rates, and hatch rates and were high and similar in each group. Viability rates for each group and the control group were 87.1%, 83.0%, 89.9% and 82.9%, respectively. Fertilization rates were 71.0%, 63.7%, 70.7% and 54.6%, whereas hatch rates were 79.2%, 85.4%, 86.8%, and 80.5%, respectively. Advancement of spawning by GnRHa had no deleterious effects on egg quality when compared to spontaneously ovulating control fish.


identifier: Mackey, Evelyn <https://research.library.mun.ca/view/creator_az/Mackey=3AEvelyn=3A=3A.html>   (2001) "Active" income support programs : a case study of improving our odds and choices- components of NCARP and TAGS.  Masters thesis, Memorial University of Newfoundland.

abstract: This thesis has no abstract


identifier: Xing, Xuemin <https://research.library.mun.ca/view/creator_az/Xing=3AXuemin=3A=3A.html>   (1999) Ad-hoc recovery in workflow systems : formal model and a prototype system.  Masters thesis, Memorial University of Newfoundland.

abstract: A workflow management system (WFMS) facilitates business processing (workflow) across distributed nodes. State-of-the-art WFMSs do not have adequate support for the dynamic changes during the workflow execution. This thesis focuses on one of the dynamic problems, ad-hoc recovery. It is a phenomenon that occurs in workflow applications when an agent needs to alter the control flow prescribed in the original definition. Specifically, we are interested in the backward ad-hoc recoveries, in which the control flow is redirected backward. When this happens, some tasks will be re-executed and consistency problems may arise. In our proposed ad-hoc recovery model, the key components of the ad-hoc recovery are defined and some constraints are given to ensure the correctness of the workflow execution. We also present a WFMS prototype, describing its design strategy and implementation method, as well as a related protocol, as one application of this model. The protocol is exemplified by a hospital workflow. Some performance issues are also discussed.


identifier: Jagdale, Ganpati Baburao <https://research.library.mun.ca/view/creator_az/Jagdale=3AGanpati_Baburao=3A=3A.html>   (1997) Adaptation to temperature in entomopathogenic nematodes.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract: The effects of recycling over a two-year period at temperatures from 10 - 25 °C were studied in four strains of entomopathogenic nematodes: Steinernema carpocapsae All strain, Steinernema feltiae NF strain, Steinernema feltiae Umeå strain and Steinernema riobravis TX strain. The main objectives of this investigation were to study the capacity for, and mechanisms involved in. thermal adaptation of a native (NF strain) boreal steinernematid nematode and to compare it with strains of entomopathogenic nematodes originating from another boreal region (Sweden; Umeå strain), temperate zone (All strain) and subtropical zone (TX strain). -- On the basis of morphometry and restriction fragment length polymorphism in ribosomal DNA spacer, a nematode that was isolated from soil near St. John's, Newfoundland, Canada, was designated as a new strain, NF, of S. feltiae. To determine whether taxonomic separations of entomopathogenic nematodes could be accomplished on the basis of physiological properties other than DNA profiles, cellulose acetate electrophoresis was used to separate isozymes of eight enzymes in infective juveniles of five strains of Steinernema. These strains comprised the four listed above, together with S. feltiae L1C strain, isolated 14 years previously from Newfoundland. Based on comparisons of the relative electrophoretic mobilities (μ) of the isozymes, it was concluded that the five isolates could be distinguished. This finding suggests that cellulose acetate electrophoresis could be an important taxonomic tool for the identification of isolates of steinernematids, provided that a combination of enzymes is used. -- The capacities for high temperatures and freezing tolerance were determined and found to be affected by the temperatures at which recycling was carried out. In all the isolates, the UT₅₀, the temperature at which 50% of the infective juveniles died, increased with increase in recycling temperature. Freezing tolerance, as measured by times at which 50% of the infective juveniles were killed (Lt₅₀) by a -5 °C regime, was reduced at higher recycling temperatures. Boreally adapted S. feltiae was more cold tolerant than S. carpocapsae and S riobravis, but its capacity to withstand freezing was reduced by recycling at warmer temperatures. The greatest capacity for heat tolerance was observed in S. riobravis, while S. carpocapsae displayed an intermediate degree of tolerance to high temperatures. -- Infectivity was found to be modified by the recycling temperatures. This was examined by measuring LD₅₀ values in G. mellonella larvae at bioassay temperatures from 5 to 25 °C. Only the infective juveniles of S. feltiae that had been recycled at 10 °C infected and killed the insects at a 5 °C bioassay temperature, whereas S. carpocapsae and S. riobravis were infective at 10 °C only when the recycling temperatures were ≤ 20 °C. The infectivity of the two strains of S. feltiae at 10 or 15 °C was compromised by propagating them at warmer temperatures (20 - 25 °C). The S. feltiae Umeå strain displayed an impaired capacity to infect hosts at warm temperatures (20- 25 °C) when recycled at colder (≤15 °C) temperatures. -- The pattern of isozymes was modified according to the recycling temperature regime. In all four isolates, isozyme banding patterns of malate dehydrogenase (MDH), marmoset-phosphate isomerase (MPl) and phosphoglucomutase (PGM) were affected by recycling or storage temperature. The two strains of S. feltiae synthesized additional isozymes of MPI and MDH or PGM in response to cold temperatures, while S. carpocapsae All strain synthesized three isozymes of MDH in response to warm temperatures. Modifications of isozyme synthesis may constitute a temperature adaptation mechanism for these nematodes. -- In all four isolates, the kinetic properties of glucose-6-phosphate dehydrogenase and hexokinase were affected by the recycling temperature. At each assay temperature (5 - 35 °C), the maximum specific activity of both the enzymes was greater in the nematodes that had been recycled at lower temperatures than in those reared at higher temperatures. In three enzyme - nematode isolate combinations, the lowest Km values occurred in nematodes that had been recycled at the lower temperatures. -- Using gas liquid chromatography, it was determined that the composition of fatty acids in total lipids and phospholipids changed adaptively with recycling temperatures. In all four isolates, the unsaturation indices of total lipids and phospholipids were increased as temperature decreased. This was due to an increase in polyunsaturated fatty acids a with concomitant decline in the proportion of saturated fatty acids, especially palmitic (16:0) and/or stearic (18:0) acids. The increase in polyunsaturated fatty acids at reduced temperatures was attributed to significantly greater percentages of linoleic acid (18:2) in total lipids and phospholipids. In all except S. riobravis, this was augmented by increased proportions of eicosapenic acid (20:5w3) at 5 °C. -- Together, these results suggest that the various recycling temperatures influenced the capacities of the entomopathogenic nematodes for temperature tolerance and infectivity at an organismal level. At the physiological level, the synthesis of isozymes, enzyme kinetics, and composition of fatty acids in lipids were modified by the recycling temperatures in an apparently adaptive fashion. The degree to which the various physiological changes provide an underlying basis for those at the organismal level is discussed.


identifier: Williams, P.G.(Paul Gareth) <https://research.library.mun.ca/view/creator_az/Williams=3AP=2EG=2E=28Paul_Gareth=29=3A=3A.html>   (1994) Acoustical and vibrational procedures for investigating the modal response of structures.  Masters thesis, Memorial University of Newfoundland.

abstract: The modal characteristics of structures are normally established experimentally through the use of accelerometers and force transducers to measure the frequency response under different excitation frequencies. Variations in the modal frequencies and the mode shapes can be determined for different structural modifications. Modal properties can also be determined through measurement of the acoustical properties of the structure, particularly in the quantity and direction of acoustic energy flow. Such measurements, because they are non-contacting, offer the advantage of eliminating modification of the modal response due to the mass of the accelerometers as well as ease of use where accelerometer attachment is difficult, for example, on fibre composite structures. Experiments were designed to investigate the ease and accuracy of such acoustic measurements by comparing results from the acoustic energy flow methods with more classical vibrational techniques. -- The structure was then modified through the introduction of a machined notch and the acoustic modal properties measured again for comparison. -- A method is presented for the use of acoustic energy flow mapping in the detection of structural defects which result in the modification of the modal frequencies and amplitudes.


identifier: Kuang, Yu Rang <https://research.library.mun.ca/view/creator_az/Kuang=3AYu_Rang=3A=3A.html>   (1996) Algebraic coupled-state calculation of positron-hydrogen collisions at low energy, using large coupling schemes.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract: The Harris-Nesbet algebraic approach is employed to carry out calculations of positron-hydrogen scattering at energy below the first excitation threshold of the hydrogen atom. The main work of this thesis is to extend the Harris-Nesbet method to large scale coupled-state calculations. With coupling schemes composed of lower physical states: 1s, 2s, 2p of both hydrogen and positronium, and a pseudo 3p of hydrogen associated with a number of short ranged correlation functions, calculations for positron-hydrogen scattering are accurately carried out for seven partial waves from L=0 to 6. Comparison with available theoretical results shows that good agreement is obtained at energies considered. Our total elastic and total Ps formation cross sections are also in good agreement with existing accurate theoretical results. Our total Ps formation and integrated cross section (total elastic plus total Ps formation) agree with available experimental data. The scattering length obtained also agree well with the existing theoretical values. There are three, two and one resonances observed for the S-, P- and D-waves below the first excitation threshold of hydrogen, respectively, which confirms the existing observations. -- On the other hand, we also carry out calculations for an 18-state and a 20-state coupling schemes. Both sets of results show reasonable agreement with each other and available findings.


identifier: Chong, Xin <https://research.library.mun.ca/view/creator_az/Chong=3AXin=3A=3A.html>   (1993) Alterations in calcium homeostasis as a possible cause of Ochratoxin A nephrotoxicity.  Masters thesis, Memorial University of Newfoundland.

abstract: The carcinogenic nephrotoxin Ochratoxin A (OTA) is a widespread natural contaminant of a variety of food and feedstuffs. The effect of OTA on renal lipid peroxidation and on renal cortical endoplasmic reticular ATP-dependent calcium uptake were investigated. -- OTA did not stimulate NADPH-dependent lipid peroxidation (malondialdehyde formation) in the kidney, either in vivo or in vitro. It also did not induce any of several antioxidative enzymes in vivo under our experimental conditions. Administration of a single high dose or multiple lower doses of OTA to rats did result in an increase of the renal cortical endoplasmic reticular ATP-dependent calcium pump activity. This increase was very rapid, being evident within 10 minutes of OTA administration, and remained elevated for at least 6 hours thereafter. This change in calcium uptake is the earliest enzymatic change reported in the kidney after OTA administration. -- In vitro preincubation of microsomes with NADPH had a profound inhibitory effect on calcium uptake. Inclusion of OTA was able to reverse the inhibition. Addition of OTA alone to cortical microsomes during calcium uptake inhibited the uptake process, although the effect was reversible. However, it does not appear that in vivo OTA exerts a significant direct inhibitory effect on renal cortical calcium uptake activity since an increase in this activity was observed after OTA administration. -- Changes in the rates of microsomal calcium uptake were correlated with changes in the steady-state levels of the phosphorylated Mg²⁺/Ca²⁺-ATPase intermediate suggesting that in vivo/in vitro conditions were affecting the rate of enzyme phosphorylation. -- Study of OTA analogues indicated that the presence of a free carboxyl group and chlorine atom on OTA contributed significantly to the effect on calcium uptake. -- These results suggest that lipid peroxidation may not be responsible for the initiating OTA nephrotoxicity. However, alterations in calcium homeostasis as evidenced by an increase in microsomal calcium pump activity could play a significant role in OTA nephrotoxicity.


identifier: Siriwardhana, Subhashinee Samudra Kumari Wijeratne <https://research.library.mun.ca/view/creator_az/Siriwardhana=3ASubhashinee_Samudra_Kumari_Wijeratne=3A=3A.html>   (2001) Almond as a source of natural antioxidants.  Masters thesis, Memorial University of Newfoundland.

abstract: Antioxidant efficacy of defatted almond whole seed, brown skin and green shell cover were investigated using a cooked comminuted pork model system. The inhibition of 2-thiobarbituric acid reactive substances (TBARS), total volatiles and hexanal by defatted almond at 2% (w/w) during a 7- day storage period ranged from 8-88, 38-90 and 57-90%, respectively. Since defatted almond products exhibited antioxidant properties, their crude extracts in ethanol were prepared at 70°C for 30 min. The total phenolic contents of ethanolic extracts of brown skin and green shell extracts were 10- and 9-times higher than that of the whole seed. Antioxidant activities of whole seed extract (WSE), brown skin extract (BSE) and green shell extract (GSE) of almond were evaluated using Trolox equivalent antioxidant capacity (TEAC) assay, β-carotene-linoleate model and bulk stripped corn oil systems. Furthermore, inhibition of DNA scission and human low-density lipoprotein (LDL) oxidation by WSE, BSE and GSE was monitored. Different free radical trapping assays were used to investigate the free radical-scavenging activity of the extracts. TEAC assay revealed that the antioxidant capacities of BSE and GSE were 13- and 10- times greater than that of seed extracts at the same extract concentration. These extracts were then tested at 100 and 200 ppm phenolics as quercetin equivalents. Retention of β-carotene in a β-carotene-linoleate model system by WSE, BSE and GSE was 84-96, 74-83 and 71-93% respectively, as compared to 2% retention in the control. In a bulk stripped corn oil system, GSE performed better than BSE and WSE in inhibiting the formation of both primary and secondary oxidation products. In a cooked comminuted pork model system GSE and BSE inhibited formation of TBARS, total volatiles and hexanal more effectively than WSE. The scavenging activity of the superoxide radical by almond seed, skin and shell cover extracts at 100 and 200 ppm was 76, 89 and 97% (100ppm), and 85, 95 and 99% (200 ppm), respectively. The corresponding reduction of hydrogen peroxide concentration was 59, 63 and 66% (100 ppm), and 86, 91 and 91% (200 ppm), respectively. The hydroxyl radical-scavenging capacities at 100 and 200 ppm were 16 and 42% for WSE, 57 and 100% for BSE and 40 and 56% for GSE, respectively. A 100% scavenging activity of the DPPH radical was achieved by both BSE and GSE at 100 and 200 ppm levels. WSE scavenged 21 and 73% of the DPPH radical at 100 and 200ppm, respectively. A total DNA retention was given by GSE at 50 ppm level against peroxyl-induced strand scission, whereas BSE and WSE reached the same at 100 ppm. On the other hand, for hydroxyl radical induced DNA strand scission, a total protection was exerted by all three almond extracts at 50 ppm level against both non-site specific and site-specific strand scission. BSE performed effectively in preventing copper-induced oxidation of human LDL cholesterol compared to WSE and GSE. All three almond extracts exhibited excellent metal chelating efficacies. High performance liquid chromatographic (HPLC) analysis revealed the presence of quercetin, isorhamnetin, quercitrin, astragalin, kaempferol-3-O-rutinoside, isorhamnetin-3-O-β-D-glucoside and morin as the major flovonoids, and caffeic, ferulic, ρ-coumaric, sinapic and gallic acids as the major phenolic acids in all three almond extracts.


identifier: Clarke, Rodney George Francis <https://research.library.mun.ca/view/creator_az/Clarke=3ARodney_George_Francis=3A=3A.html>   (2000) Amino acids under hydrothermal conditions : apparent molar volumes, apparent molar heat capacities, and acid/base dissociation constants for aqueous α-alanine, β-alanine, glycine, and proline at temperatures from 25 to 250°C and pressures up to 30.0 MPa.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract: Amino acids are members of a unique group of compounds that exist in solution as zwitterions. Yet the thermodynamic properties of aqueous amino acids have not been measured at temperatures above 343 K. The amino acids studied in this work have been chosen based on their hydrothermal stability and their solubility in water. A series of batch experiments confirmed that aqueous α-alanine, glycine, and proline were stable on the time scale required for our measurements at the temperatures, pressures, and molalities required for this work. -- The apparent molar volumes Vɸ of aqueous α-alanine, β-alanine, and proline have been determined using platinum vibrating tube densitometers at temperatures from 298 K to 523 K and at pressures from steam saturation to 30 MPa. Values of the standard partial molar volumes V° for the aqueous amino acids increase with temperature, then deviate toward negative values at temperatures above 398 K, consistent with an increase in the critical temperature in the solutions relative to water. The apparent molar heat capacities Cp,ɸ of aqueous α-alanine, β-alanine, glycine, and proline have been determined using a differential flow calorimeter and a Picker flow microcalorimeter at temperatures from 298 K to 498 K and at pressures from steam saturation to 30 MPa. Values of the standard partial molar heat capacities C°p for the aqueous amino acids increase with temperature, then deviate toward negative values at temperatures above 373 K to 423 K, also consistent with an increase in the critical temperature in the solutions relative to water. The values of both V° and C°p  increase with increasing pressure. Comprehensive equations to describe the standard-state properties over the experimental temperature range are reported. -- The deviation toward negative values by V° and C°p is opposite to the behavior predicted by the correlations developed by Shock and Helgeson (Geochim. Cosmochim.  Acta. 54, 915-945, 1990) and Amend and Helgeson (J. Chem. Soc, Faraday Trans. 93, 1927-1941,1997). The temperature dependence of V° and C°p predicted using the very recent functional-group additivity model of Yezdimer et al. (Chem. Geol. 164, 259-280, 2000) is only in qualitative agreement with the experimental results. The contribution to V° and C°p from the solvent polarization by the large dipole moment of the zwitterions deviates toward negative infinity as Tc is approached, in a manner similar to the experimental values of V° and C°p for each of the aqueous amino acids. While this agreement is qualitatively consistent, it is not quantitatively consistent, which suggests that the non-electrostatic hydration effects are of similar magnitude to the solvent polarization effects. -- The acid/base dissociation constants for aqueous α-alanine have been determined from 423 K to 523 K using a UV-visible spectrophotometer and the colorimetric indicators developed by Xiang and Johnston (J. Sol. Chem. 26, 13-30, 1997) and Ryan et al. (J. Phys. Chem. 101, 1827-1835, 1997). The dissociation constants that were estimated with the functional-group additivity model of Yezdimer et al. (Chem. Geol. 164, 259-280, 2000) and those obtained from the isocoulombic extrapolation of room temperature data were found to be an upper limit for the measured values. The contribution of non-zwitterionic forms of the aqueous amino acids to the experimentally determined values of V° and C°p were negligible at all but the highest temperatures. -- In this work, the first experimentally determined apparent molar volumes Vɸ for aqueous α-alanine, β-alanine, and proline were obtained at T ≥ 343 K. The first experimentally determined apparent molar heat capacities Cp,ɸ for aqueous amino acids at T ≥ 328 K were obtained in this work. The first experimentally determined acid/base dissociation constants for aqueous α-alanine obtained at T ≥ 423 K were also obtained in this work.


identifier: MacGregor, Fiona M. <https://research.library.mun.ca/view/creator_az/MacGregor=3AFiona_M=2E=3A=3A.html>   (1999) Agents of change : women creating web pages.  Masters thesis, Memorial University of Newfoundland.

abstract: The Internet as a social phenomenon has only just begun to affect the everyday lives of individuals. Studies of women's use of personal computers suggest that women may be less likely than men to engage in Internet usage. Various surveys support the fact that there are currently more men than women using the Internet. While there are women who do not use the Internet there are also women who have become intensely engaged in it. Women who make intensive use of the Internet have been labelled as grrrls and their presence is particularly visible on the World Wide Web (WWW). -- In an attempt to understand how the 1980s view of women as hesitant computer users gave way to the technologically competent grrrl image, this thesis examines the experiences of some of the women who create web pages, and the world of women web page designers. Findings address who these women are, how they learned to create web pages, and their experiences as WWW page designers. -- Clement and Shade's (1996) access rainbow, which addresses the social and technical factors needed to access the Internet, and actor network theory which looks at the translation of power between humans and non-humans (e.g. machines), provide a theoretical and political context for the investigation. -- Perceptions about the visibility of gender on the Internet emerged from the sixty-seven participant responses to an on-line survey. These perceptions have been categorized as women as agents of inequality (women who see gender as inescapable on the Internet) and women as agents of choice (women who see gender as an individual choice on the Internet). Results suggest that these perceptions might be related to age.


identifier: Wells, Patricia <https://research.library.mun.ca/view/creator_az/Wells=3APatricia=3A=3A.html>   (2002) An analysis of faunal remains from two Groswater Palaeoeskimo sites at Port au Choix, northwestern Newfoundland: Phillip's Garden West (EeBi-11) and Phillip's Garden East (EeBi-1).  Masters thesis, Memorial University of Newfoundland.

abstract: This research involves the examination of faunal remains from two Groswater Palaeoeskimo sites on the Point Riche Peninsula, northwestern Newfoundland. The purpose of this study is to understand the settlement and subsistence patterns of the inhabitants of Phillip's Garden West and the adjacent site of Phillip's Garden East. A thorough examination of the faunal remains allows a quantified presentation of the species exploited and season of occupation. The most important species exploited at these sites is seal, particularly the harp seal that still frequents this coast. An examination of the frequency of seal body parts at the sites allows a discussion of the processing of this vital resource. In addition, seal body part frequency offers insights into the nature of the occupation at both sites, and supports interpretations of Phillip's Garden West as an important location for ritual activity associated with seal exploitation.


identifier: Moulton, Valerie D. <https://research.library.mun.ca/view/creator_az/Moulton=3AValerie_D=2E=3A=3A.html>   (1997) Activity and haul out behaviour of captive harp seals (Pagophilus groenlandicus).  Masters thesis, Memorial University of Newfoundland.

abstract: The annual cycle of all pinnipeds includes seasonal changes in behaviour linked to key events such as reproduction, moult, and in some species, migration. These changes in behaviour have generally been quantified in terms of haul out or diving, but rarely for more than one season. Weather conditions have been shown to influence the haul out pattern of some pinniped species but these studies have also had limited seasonal scope. This study measured activity levels (seal body movements per minute) and haul out behaviour of nine captive harp seals (Pagophilus groenlandicus) using modified time-depth recorders for a fourteen-month period. Solar radiation, temperature, wind velocity, and relative humidity were concurrently monitored throughout the study. The harp seal was selected for study because relatively little quantitative information exists for this species' behaviour and because circannual patterns in their food intake and energy demands have been detected. -- Activity levels and amount of time spent hauled out varied seasonally for most harp seals, but individual variation often precluded generalization. However, certain trends occurred during key annual cycle events. Seals spent significantly more time hauled out, and time of day of haul out shifted closer to midday during moult. Increasing wind velocity had a negative influence on haul out during this time, whereas solar radiation had a positive effect. These behavioural responses to weather conditions are energetically beneficial to seals, because exposure to warm temperatures accelerates the growth of skin and hair. Activity significantly increased in only two seals during the breeding period. Seasonal patterns of daily activity and haul out were overlaid by circadian rhythms. Activity consistently peaked around midday and was lowest at night when seals were found to haul out The midday feeding schedule probably acted as an "entraining" mechanism for these rhythms. This suggests that factors like habits of prey (i.e., availability or ease of access) may play a role in determining the daily activity patterns of harp seals in the wild. Although no conclusive evidence exists to support this idea, daily dive patterns of several other seal species and the behaviour of their prey suggest that it is true.


identifier: Powers, Gwendolyn Jean <https://research.library.mun.ca/view/creator_az/Powers=3AGwendolyn_Jean=3A=3A.html>   (1975) Teacher perceptions of the need and helpfulness of elementary guidance and reading consultant services.  Masters thesis, Memorial University of Newfoundland.

abstract: The purpose of the study was to ascertain teachers perceptions of the level of need and helpfulness for a list of twenty functions which can be performed by either a guidance or a reading consultant or both. -- A questionnaire was devised by the researcher and a pilot study conducted to check the questionnaire's face validity. Following minor revisions the questionnaire was mailed to 429 teachers employed by the Avalon North and Avalon Consolidated School Boards, near St. John's, Newfoundland, who had access to the services of both reading and guidance consultants. Two hundred and fifty-five teachers completed and returned the questionnaire. -- The teachers who participated in the study felt the greatest need for consultation services was in the area of learning difficulties. Reading consultants were perceived most helpful in providing information on new developments in reading. The guidance consultant was felt to be most helpful in assessing intellectual abilities through the use of standardized tests. -- The teacher perceived role of the consultant, as inferred from the median ratings for need, was not consistent with the role of either guidance or reading consultants as outlined in the literature. The role performed by the guidance consultant, as inferred from the helpfulness ratings, differed from the role outlined in the literature while that for the reading consultant was more consistent. -- A comparison of the perceived level of need and helpfulness for each function showed large differences in the provision of in-service training sessions by guidance consultants, the conducting of demonstration lessons in reading by the reading consultant and the perceived level of need for these services. -- An analysis of the data according to certain demographic variables indicated significant differences for both need and helpfulness when grouped according to the grade level taught. The helpfulness ratings for reading consultants, when grouped according to teaching experience and level of teaching certificate, were also significantly different. -- The conclusions and recommendations of the study provide a guideline for improving the consultation services now being provided.


identifier: Shears, Margaret Ann <https://research.library.mun.ca/view/creator_az/Shears=3AMargaret_Ann=3A=3A.html>   (1983) Zinc metabolism in the winter flounder (Pseudopleuronectes americanus).  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract: The gastrointestinal uptake of Zn²⁺ was studied in the winter flounder using an in situ technique, an equilibrium dialysis technique and a non-absorbed marker technique. -- The entire digestive tract of the flounder was capable of absorbing Zn²⁺, with the uppermost portion of the intestine having the highest and the stomach the lowest capacity. A seasonal study revealed that the capacity to absorb Zn²⁺ was greatest during the summer feeding period. Zn²⁺ absorption appeared to involve at least two steps, the first a rapid accumulation of Zn²⁺ by the tissue and the second, a slower transfer of Zn²⁺ into the body. The total amount of Zn²⁺ absorbed increased with increasing loads of Zn²⁺ in the lumen; the transfer mechanism did not appear to be saturated at the highest Zn²⁺ loads tested. However, Zn²⁺ uptake was inhibited by several other metals and by the amino acid, histidine. -- The capacity of the digestive tract to absorb Zn²⁺ was not affected by feeding the flounder a high-Zn²⁺ diet or by increasing the body Zn²⁺ load by parenteral injections. In the event of exposure to elevated levels of Zn²⁺ in the diet, it is suggested that elimination mechanisms may play a greater role in Zn²⁺ homeostasis in the winter flounder than limitation of gastrointestinal uptake. -- The dynamics of Zn²⁺ turnover in the flounder was investigated by examining the distribution of ⁶⁵Zn in the tissues following single intramuscular injections of the radiotracer. The tissues exhibited different rates of accumulation and loss of ⁶⁵Zn, the most rapid being in tissues such as the kidney, liver, gill and gastrointestinal tract. -- Retention of ⁶⁵Zn was examined in live flounder using a whole-body detector. The loss of ⁶⁵Zn appeared to vary seasonally; when flounder were monitored during the summer feeding period the rate of ⁶⁵Zn loss (monitored in the area of the peritoneal cavity) increased over that seen in the winter non-feeding period (i.e. TB₁/₂=223 and 1510 days, respectively). Whole-body ⁶⁵Zn retention patterns were similar in flounder injected with saline or a load of stable Zn²⁺. Under these experimental conditions the rate of Zn²⁺ loss was not affected by an excess of stable Zn²⁺. -- Experiments conducted to determine the possible site(s) of Zn²⁺ excretion into the digestive tract following i.v. injections of ⁶⁵Zn indicated that Zn²⁺ could be secreted into the lumen contents all along the tract. Other possible sites of Zn²⁺ elimination include the gills, kidney and body surface. -- Chromatographic techniques were its ed. to examine the Zn²⁺-binding proteins in the cytosols of several tissues of the winter flounder. A low molecular weight ⁶⁵Zn (Zn²⁺)-binding protein, with properties characterizing it as metallothionein, was isolated from the mucosal and liver cytosols of Zn²⁺-injected flounder. Metallothionein did not appear to be serving the same function(s) in the intestine of the flounder as commonly hypothesized for mammals. The presence of the protein in the mucosal cytosol did not appear to be associated with any enhancement or depression of Zn²⁺ absorption. The role of metallothionein in the normal metabolism of Zn²⁺ in the flounder remains to be resolved. That it could play a role in homeostasis is suggested by the presence of a low molecular weight Zn²⁺-binding protein, with elution characteristics similar to metallothionein, in the tissues of normal flounder.


identifier: Kini, Deepak P. <https://research.library.mun.ca/view/creator_az/Kini=3ADeepak_P=2E=3A=3A.html>   (2002) Evaluation of safety of transdermal drug delivery using electroporation by In vitro and In vivo studies.  Masters thesis, Memorial University of Newfoundland.

abstract: Introduction: Transdermal electroporation involves the application of high voltage electrical pulses for microsecond to millisecond duration to produce reversible increase in permeability of skin. It can provide an alternative route to intravenous injection for the fast delivery of macromolecules molecules such as proteins and peptide drugs in clinically effective amounts for the patient. However, the mechanism of electroporation and its safety are unclear. Hence, electrical parameters for delivery of individual drugs have to be chosen empirically or by careful optimization. -- Objectives: To carry out optimization of electrical parameters using fuzzy rat skin tissue in vitro for delivery of terazosin hydrochloride (TRZ), followed by use of these parameters in live fuzzy rats (in vivo), to study their safety and effectiveness. To design in vitro and in vivo tests to predict the safety of this technique. -- Materials: Side-by-side diffusion cells were used for in vitro and in vivo studies. Ag/AgCI electrodes of different areas were used to deliver the exponentially decaying electroporation pulses from a Gene Pulser® (BioRad Laboratories, USA). Fuzzy rats and freshly excised full thickness skin from fuzzy rats were used for in vivo and in vitro studies respectively. -- Methods: Pulse length and rate of pulsing were evaluated with respect to their ability to reverse the increased permeability caused by electroporation. The correlation between TRZ concentration and increase in electroporative delivery was studied. Based on above studies optimal parameters were chosen to deliver TRZ in vivo. Their safety and effectiveness were compared to delivery without electroporation (control). Pharmacokinetic parameters were estimated by giving drug intravenously and subcutaneously. In vivo impedance recovery of skin after electroporation to pre-electroporated state was studied to predict safety. Similarly, uptake of glucose by skin with or without electroporation was studied to predict change in viability (damage) in vitro. Finally, electrodes of different area were characterized in vitro with respect to the electrical parameters. These parameters in conjunction with the in vitro and in vivo drug delivery and safety studies would throw some light on the mechanism of electroporation and the effect of electrode area on drug delivery and safety by electroporation. -- Results and discussion: If electroporation is completely reversible then the rate of transport of drug through the skin after stopping electroporation pulses should be the same as that through non-pulsed skin. Using this method an applied voltage (Uelectrode.0) of 400V, a pulse length of 20 millisecond and a rate of pulsing of 10 pulse per minute (ppm) were found to be relatively safe and delivered significantly higher drug compared to passive drug delivery. Increased donor concentration gave higher delivery and may help in reducing exposure to higher electrical conditions to produce same amount of drug delivery. In vivo studies showed that TRZ can be delivered safely and effectively with electroporation. However, the effect of electrode area needs to be studied further. Pharmacokinetic studies indicated depot formation within skin after electroporation and this could be due to limited blood flow to the skin. In vitro biochemical studies showed a lag time in lactate production when a very high voltage electroporation pulse was used and there was a general stimulation of lactate production (as a result of glucose utilization) after electroporation compared to non-electroporated skin. The lag time may be used to predict damage due to electroporation. In vitro electrode characterization studies gave considerable insight into the observed drug delivery profiles and the differences in safety profiles between the different electrodes. In vivo impedance studies showed that complete recovery of skin impedance after electroporation might take hours to days. Recovery was faster with shorter pulse lengths and lower number of pulses. -- Conclusions: An applied voltage of 400 V, 20 pulses of 20 millisecond at the rate of 10 pulses per minute with 10% TRZ in contact with skin and using a small area electrode was found to be relatively safe and effective for delivery of TRZ in vitro and in vivo, with higher delivery for higher electrode area as predicted. The in vitro electrode characterization experiments could explain some of the observed differences between the drug delivery by different electrodes and in vitro viability studies could predict damaging electrical conditions. In vivo impedance studies showed that the parameters which can cause appreciable recovery of impedance after electroporation, are those that have not shown to deliver appreciable amount of drug in vitro, at least by electroporation alone. New electrode designs or new methods will have to be devised to increase safety of electroporation before electroporation can be considered useful or tested on humans.


identifier: Bochdansky, Alexander Boris <https://research.library.mun.ca/view/creator_az/Bochdansky=3AAlexander_Boris=3A=3A.html>   (1997) Feeding physiology of the cold water appendicularian Oikopleura Vanhoeffeni (Tunicata).  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract: Clearance and ingestion rates, behavior, gut passage time, pigment degradation and assimilation efficiency were examined for Oikopleura vanhoeffeni (Appendicularia, Tunicata) in a gradient of concentrations of laboratory grown diatoms. Data from particle removal experiments and behavioral observations showed similar trends, although the magnitude of the responses varied depending on the technique used. Clearance rate decreased significantly with food concentration, although saturation was not reached for a particle concentration range representative of conditions in the field. No lower feeding threshold was found. Clearance rate also decreased with the age of the external filtering device (i.e. house). For an individual animal, a wide range of clearance rates can be encountered from 0 to a physiological upper limit given by the Morris and Deibel (1993) model. Using body size, tail beat frequency and proportion of time spent feeding from in situ observations it was possible to estimate clearance rate in the field. The means of these estimated clearance rates were within a threefold range of the means of five alternative methods. The mean gut passage time of O. vanhoeffeni was 0.8 h and was independent of trunk length and particle concentration, although it varied significantly among individuals. Studies with ⁶⁸Ge incorporated into the silica frustules of diatoms as a conservative tracer, showed that chlorophyll a conversion (i.e. degradation into fluorescent and non-fluorescent breakdown products) was on average 79%. The chl a conversion was not related to the amount of food in the gut estimated by visual inspection, although it was inversely correlated with the amount of ⁶⁸Ge and chl a recovered in the guts of animals. Assimilation efficiency of bulk diatom carbon was 67%. Extraction in various solvents allowed fractionation of food and feces into four main biochemical pools. Proteins and low molecular weight compounds were preferentially absorbed by the animals over lipids and polysaccharides. Predicted C:N ratios (by weight) for fecal pellets produced on a diatom diet ranged from 6.0 to 7.2, depending on the formula used and were consequently not much higher than the C:N ratios of the ingested diatoms (C:N = 5.2 - 6.3). The results of this thesis are relevant for the calculation of realistic population clearance rates as well as for the biochemical transformation of sinking material as appendicularians in general are major grazers in the world oceans.


identifier: Bhuyan, Gouri Shankar <https://research.library.mun.ca/view/creator_az/Bhuyan=3AGouri_Shankar=3A=3A.html>   (1986) Fatigue life prediction of offshore tubular T-joints using fracture mechanics approach.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract: The thesis presents the results of an analytical and experimental investigation of the fatigue behaviour of tubular T-joints, using a linear fracture mechanics approach. The analytical study includes the development of a finite element computer program to analyse tubular joints with/without weld toe cracks. The experimental investigation consists of quantifying the effects of sea water, temperature, frequency, load ratio and wave form on fatigue crack-growth-rates in CSA G40.21 M 350 WT steel, which has been'proposed for the Canadian Offshore. -- The actual curved surface and the brace/chord intersection are approximated by the assemblage of flat quadrilateral and triangular plate elements for two dimensional analysis. The analysis uses a plane stress element to account for membrane stiffness and a plate bending element to account for flexural stiffness.  For three dimensional analyses, chord/brace/weld regions are modelled using incompatible brick and prism elements. In order to reduce the computer storage requirements as well as the solution costs, the region of high stress gradient is analysed using the rezone technique. Hot spot stress and stress concentration factors obtained from these analyses are compared with the experimental values available in the literature. -- To study the effect of a shallow weld toe crack on through-thickness and surface stress redistribution, the region at the vicinity of the crack is modelled using special elements which produce singular stress fields at the crack front.  The crack-tip stress intensity factors are determined by comparing the crack-tip stresses, obtained from the analyses, with the available theoretical solutions. -- Fatigue crack-growth-rate data and material coefficients, C and m, for various temperature, load ratio and frequency ranges are obtained from compact tension specimen tests in air as well as in sea water. Knowing the crack-growth behaviour in the base metal, the through-thickness-cracking lives of tubular T-joints are predicted analytically using the modified Paris' equation and the estimated lives are compared with reported experimental results. The accuracy of the computer program and the validity of the proposed method for predicting fatigue life of tubular joints are checked by testing a prototype tubular T-joint.


identifier: Parsons, Amanda <https://research.library.mun.ca/view/creator_az/Parsons=3AAmanda=3A=3A.html>   (2008) Identification and characterization of a novel interaction between peroxisome-proliferator activated receptor gamma (PPARγ) and mesoderm induction-early response: implications for adipogenesis.  Masters thesis, Memorial University of Newfoundland.

abstract: PPARγ is a nuclear hormone receptor and master regulator of lipid metabolism and adipogenesis. PPARγ regulates these processes through the recruitment of a diverse set of transcriptional coregulators in a tissue and time specific manner. This study focused on characterizing the interaction between PPARγ and mesoderm induction early response 1 (MIER1), a transcription factor that has been shown to interact with other nuclear hormone receptors and regulate target gene expression. Glutathione S transferase pull-down assays have revealed that PPARγ interacts with both MIER1α and β through the common SANT domain. Coimmunoprecipitations in HEK-293 (human embryonic kidney cells) confirmed that this interaction occurs in vivo. A transcriptional reporter assay using luciferase regulated by the PPAR response element (PPRE) demonstrated that MIER1α and β cause a ligand-independent 2-fold activation of PPAR-driven transcriptional activity and this was similar to the 3-fold activation observed with a known PPARγ coactivator (PGC1-α). Thus, MIER1 interacts with PPAR in a ligand-independent manner through its SANT domain, and activates PPARγ -mediated transcriptional activity. PCR analysis showed that MIER1 mRNA expression is upregulated in 3T3-L1 pre-adipocytes during their differentiation into adipocytes. As well, immunocytochemistry revealed that MIER1α is highly expressed specifically in differentiated 3T3-L1s. Future work will determine the exact role of MIER1 in adipogenesis, using shRNA to knockdown MIER1α in the well-established 3T3-L1 differentiation system.


identifier: McFadyen, Catherine <https://research.library.mun.ca/view/creator_az/McFadyen=3ACatherine=3A=3A.html>   (2008) A dynamical systems approach to modeling mercury contamination in aquatic food webs.  Masters thesis, Memorial University of Newfoundland.

abstract: Unacceptable mercury levels have frequently been observed in the fish of Boreal forest lake systems. Because of this, fish consumers are at risk for mercury exposure through fish consumption. Populations relying heavily on dietary fish are particularly at risk. The Innu population in Labrador is one such group of people. They catch fish year-round from a variety of lakes in Labrador. Some species of fish harvested by the Innu have been shown to accumulate high levels of mercury that surpass consumption guidelines. This is of great concern because mercury is a neurotoxicant and can have adverse health effects including reproductive impairment, growth inhibition, developmental abnormalities, and altered behavioural responses. -- We have developed a dynamical systems model to predict the effect that certain environmental changes have on the mercury content of food fish in lake systems. We model the aquatic system using a system of ordinary differential equations which relate the biomass of fish in the highest trophic levels with the amount of methyl mercury in these fish populations and in the environment. We look at factors such as harvesting rates, intrinsic growth rates of populations, mercury absorption rate, and rate that mercury is introduced to the lake environment. We also examine the effect that seasonal temperatures and spring snow melt has on the system. -- Dynamical systems models are often used in biology but have rarely been used to examine situations involving contamination of aquatic environments. The models described here are original models; to our knowledge, these are the first dynamical systems models developed to model an aquatic contaminant that is not lethal to the population. -- The model predicts that when mercury enters the lake at a constant rate a stable equilibrium state will be reached eventually. The time taken to reach this equilibrium will vary depending on rate of mercury input. Using parameter values applicable to Boreal forest lakes, the time taken to reach equilibrium is predicted to be approximately 15-20 years, and the final mercury concentration is predicted to be 0.4 ppm for prey fish and 0.655 ppm for top predator fish. When the seasonal effect of colder temperatures and spring snow melt is considered, the lake system exhibits yearly cyclical behaviour. This model predicts fish mercury concentrations very similar to the nonseasonal model. The models described here were shown to be sensitive to methyl mercury input to the lake, methyl mercury output from the lake, and predator functional response.


identifier: Churchill, Kimberley <https://research.library.mun.ca/view/creator_az/Churchill=3AKimberley=3A=3A.html>   (2009) Covert contrast in the speech of an adolescent with Apraxia of Speech : a case study.  Masters thesis, Memorial University of Newfoundland.

abstract: This is a case study of Marshall, a 15-year-old with Apraxia of Speech (AoS). AoS is an articulatory disorder affecting ability to program speech musculature. This thesis examines Marshall's production of the approximants /r, l, w, j/. In singleton onsets Marshall's /r/ sounds like /w/, ‘red’ [wεd]. For reasons outlined in the thesis, we expect Marshall to produce a contrast between /w/ and /r/ in singleton onsets, however, Marshall appears to produce both as [w]. This apparent lack of contrast prompted this investigation into the possibility of a “covert” contrast between /r/ and /w/ (a difference that is measurable but not perceivable to listeners). Marshall's approximants in singleton onsets were acoustically analysed. Statistical analysis revealed contrasts between all four approximants. Furthermore, acoustic correlates of /r/ and /w/ were statistically different indicating covert contrast. Verifying the existence of covert contrast in an individual with AoS may have implications on the diagnosis and treatment of such speech disorders.


identifier: Walsh, Meghan Christine <https://research.library.mun.ca/view/creator_az/Walsh=3AMeghan_Christine=3A=3A.html>   (2007) Assessing the care requirements and perceptions of elderly applying to long-term care: the need for alternatives to institutionalization along the continuum.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract: Despite changes in the 1990's to the long-term care system in the Eastern Health region of Newfoundland and Labrador problems persisted. The system continued to be plagued by inappropriate use of nursing home beds, unnecessary acute care use, a discrepancy between the supply and demand of nursing home beds and a deficit of housing and alternatives to institutional care. Research suggested that a portion of applicants to the single-entry system with modest care needs might be better suited to an alternative housing arrangement rather than the two existing options: personal care homes and nursing homes. With the high cost of nursing home beds, lengthy wait times for placement, and a lack of interest in personal care homes, these issues demanded further investigation. The purpose of the study was therefore to gain an in-depth understanding of the system from a segment of applicants with modest care needs that could be extrapolated to a larger population of applicants with similar needs. Consequently, a chart review of an incident cohort of elderly applicants for long-term care placement was conducted to determine disability levels and support requirements. Data collected included care requirements and functional status, acute and chronic care usage, stated preferences for facilities and reasons for application, presence and use of formal and informal support, wait times, and outcomes of applications. In the second phase of the study, twenty individuals from the incident cohort were interviewed using grounded theory to explore experiences of the elderly with long-term care and the meanings of their decisions in relation to their personal experiences of aging and more specifically, the application process. Additionally, the objectives were to determine participants' perceptions of their needs; reasons for and causes of the decision to apply for long-term care placement; the role of applicants' support networks; attitudes regarding existing options; and, finally, opinions regarding a theoretical alternative housing option. --  The quantitative findings confirmed: that, firstly, many applicants with modest care needs would be better suited to an alternative housing arrangement (such as a supportive housing) rather than present options; that there are significant problems regarding both informal and formal supports of many applicants; and, lastly, emphasized the important role of critical episodes in many applications. The qualitative research found study participants made continual adjustments and readjustments to all facets of their lives including their environment, support and social networks, expectations and self-identities to avoid moving to a home as their needs increased. It was found that a weighing of support occurred between participants' existing circumstances and the expectation of support they viewed they would receive in a home. The inconsistencies in their support network and growing difficulties maintaining independence were measured against the perceived consistent care a nursing home or personal care home could provide. A gradual reconciliation to the move occurred, making the decision increasingly easier, while one or more critical episodes - such as a loss of a spouse or sudden decline in health - commonly acted as a trigger in the decision to apply for long-term care. It was found, however, that the decision-making process occurred in stages and that it extended beyond the application to the time of placement, which signified the actual final decision to applicants. The findings suggest that a comprehensive integrated system of long-term care services combined with a range of accessible, alternative housing options designed to avoid or delay placement would reduce demand on the system from the elderly without professional care requirements.


identifier: Yasar, Oznur <https://research.library.mun.ca/view/creator_az/Yasar=3AOznur=3A=3A.html>   (2008) Algorithmic complexity and extremality characterizations for edge searching and its variations.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract: Edge searching is a combinatorial game played on graphs. The aim is to construct a search strategy to catch an intruder hidden in the graph independent of his actions. If the intruder has a diffused form then searching corresponds to cleaning the graph. A related problem consists of minimizing the number of searchers used in this search. Various versions of edge searching have been introduced in the past depending on how searchers and the intruder can move. In this dissertation we define Weighted Search and Fast Search as two new variants and answer some complexity and extremality problems. -- Weighted Search corresponds to cleaning a contaminated graph where edges may have different capacities. The main result we have is that Weighted Search is an NP-complete problem. We also give comparison results such as bounds on the weighted search number in terms of related graph parameters including pathwidth. We characterize those graphs which two searchers can clean. -- Fast Search is an internal monotone search where no edge is  traversed more than once in a non-weighted graph. We present a linear time algorithm to compute a fast search strategy for a given tree. We investigate the fast search strategies for bipartite graphs. -- The construction of k-searchable graphs, those graphs which k searchers can clean, has been of major interest. Graphs that are 1,2 or 3-searchable have been completely characterized previously, whereas characterizing 4-searchable graphs was left as an open problem. We solve this problem partially and give insights for future work.


identifier: Rowsell, Dean Francis <https://research.library.mun.ca/view/creator_az/Rowsell=3ADean_Francis=3A=3A.html>   (2008) Application of coherent radar using stepped frequency modulation: an evaluation of a practical, narrowband design.  Masters thesis, Memorial University of Newfoundland.

abstract: Coherent radar is poised to supersede traditional (typically magnetron-based) radar in a vast array of applications, that until recently could not bear the high cost of coherence. The reason for this is that the wireless communications age has accelerated the development of enabling technologies and tremendously improved associated costs. -- Coherent radar systems are capable of equaling or exceeding the performance of traditional radar, at power levels reduced by up to several orders of magnitude. To accomplish this, an equivalent energy is distributed over time using special modulation schemes, such as stepped-frequency-modulation (SFM). SFM is a multi-parameter waveform, so much of the understanding of the effects of different parameter sets can be attained through simulation and investigation of ambiguity responses. Such investigation led to the development of generalized ambiguity patterns for SFM that provide a reference for understanding the impact of changing the waveform parameters. SFM can also be inherently exploited in receiver design since its bandwidth is linearly distributed over time. Therefore, a receiver can be dynamically and synchronously tuned  so that instantaneous reception is over a narrow bandwidth-effecting cost savings in the digitizing hardware. An algorithm has been  developed, called an isomorphic matched filter, to support this method. --  To investigate the practical aspects of coherent radar, a research program was launched at C-CORE to design and implement a radar prototype and conduct a field assessment. This research  program yielded a working prototype that was subjected to a variety of field exercises. The results showed that the performance, in terms of range and Doppler resolutions, predicted by theory and simulation was indeed realizable, and with a radar platform constructed for moderate cost. -- An SFM-based, scanning, coherent radar carries many configuration possibilities. A simple model was developed to consider various parameter sets associated with the SFM waveform and the scanning platform. The model predicts  achievable resolutions and range constraints in particular. One interesting finding is that the SFM waveform does not lend itself, simultaneously, to target detection at both short range and long range, and that the signal parameters can only be optimized for one or the other. Operationally, this implies that if both near range and far range data is needed, strategies must be decided upon to render such data to the user (e.g., alternate the parameter set in successive scans). -- While the radar prototype was well-suited to fulfilling the objectives of the research program, it is not in a form suitable for demonstration in real operational scenarios. To accommodate this, the next design iteration must incorporate the following elements: azimuth scanning; a much higher level of integration in the hardware; and, support for real-time processing and rendering of the radar output. This research provides a sound foundation for further development and commercial exploitation of SFM-based coherent radar. It is recommended that such development focus on producing a prototype that can be placed in real operational scenarios in order to fully assess the utility of the technology.


identifier: Fanous, Ihab F. Z. <https://research.library.mun.ca/view/creator_az/Fanous=3AIhab_F=2E_Z=2E=3A=3A.html>   (2008) Advances in robust methods for limit load analysis.  Doctoral (PhD) thesis, Memorial University of Newfoundland.

abstract: Limit load analysis is an essential tool in engineering analysis. Several methods were developed for both the upper and lower bound limit load multipliers. Several methods are developed with the objective of having a simplified analysis procedure to evaluate the limit  load without the use of complex inelastic analysis. The recently developed lower bound solutions are either conservative or have some limitations in their applications. The redistribution node method was developed earlier as a lower bound limit load solution using the  iterative elastic finite element analysis. It was applied to several two dimensional problems. -- In the present work, the iterative R-Node method is introduced as a tool to calculate the lower bound limit load of a component. The method interprets the redistribution of the  stress to find the reference stress which is used to calculate the limit load. The applicability of the iterative R-Node method to complex three dimensional problems is investigated. This includes applications with three dimensional shell and solid brick elements. Single and multiple loads are also applied to. Also, the results are used to help in the stress classification of the finite element analysis results according to the American Society of Mechanical Engineers codes. -- Finally, the reference volume limit load analysis was developed in previous research using the m° upper bound solution. It was shown that it has a high convergence rate when compared to the other analysis methods. In this work, the method is redeveloped using the classical upper bound multiplier. The applicability of the method is verified for complex three dimensional geometries modeled using shell and solid elements.


identifier: Higdon, John Lawrence <https://research.library.mun.ca/view/creator_az/Higdon=3AJohn_Lawrence=3A=3A.html>   (2008) An experimental approach to Inuit ground stone technology at Nachvak Fiord, Labrador.  Masters thesis, Memorial University of Newfoundland.

abstract: lthough nephrite use has been studied from various perspectives in many parts of the world (Asia, Mesoamerica, and western Canada), discussion of its use amongst the precontact Inuit of Labrador is limited. Archaeologists have discussed possible nephrite sources in Labrador in the past, but have not dealt directly with its exploitation. Focusing mainly on the nephrite assemblage recovered from Nachvak Village (IgCx-3) in northern Labrador, the difficulties associated with nephrite procurement, manufacture and use are discussed. The fibrous crystalline structure that gives nephrite its strength and durability also makes it very difficult to work. Concepts of agency, chaîne opératoire and anthropology of technology are used to characterize the ground stone assemblage according to provisional function and stage in the production process. Based on the tools and implements available, the experimental production and use of drill bits are discussed in order to assess the costs and benefits of using nephrite as opposed to slate. Successes and failures associated with the experimental approach are also discussed to highlight the learning process, as well as the nuances of Inuit ground stone technology.