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Production of cryogens using wind energy for use in deep mine cooling and ventilation.
No full textThis research work, named as ‘CryoVent’, was focused on determining the feasibility of using
wind energy, to produce liquefied gases (cryogens) continuously in a safe approach that can be
used for the cooling and ventilation of underground mines. The experimental work performed
suggested that the continuous production of liquefied gases with variable input work is practical.
The average specific power consumption for liquefaction of nitrogen in this work was 7.86
kWh/kg using the refrigeration produced by helium. This is ~20 times higher than that consumed
by industrial scale gas liquefaction systems, but is practical for a small scale system. This
specific power consumption could probably be lowered if the working fluid itself is liquefied.
Analysis on wind speed variability and wind speed data synthesis were also performed
which suggested presence of multi-fractal nature in wind speed data that represent the temporal
variation. A new method developed to generate high sampling frequency wind speed data from available low sampling frequency wind speed data can have contribution in all sectors when
there is a need of higher sampling frequency time series data for simulation/study purposes.
The liquid nitrogen mass flow rate (kg/s) increased with increase in compressor motor
frequency and also when operating at variable motor input frequency. However, the average
compressor power consumption also increased compared to average power consumption
during operation at standard motor frequency of 60 Hz. This was in a laboratory scale
liquefaction system and needs to be tested in the large scale system experimentally. With 1 kg/s
of liquefied nitrogen supplied, ~459 kWr of cooling power is available to cool the deep mine air
which is at 30-400C. A volumetric flow rate of 0.062 m3/s of liquefied air can provide a cooling
power equivalent to that provided by a volumetric flow rate of 4000 m3/s of atmospheric air,
which is the requirement of some of the biggest mines in the world. The hydraulic wind turbine as proposed in this work can eliminate the system start-up
issues following the calm period, which are typical concerns with the wind energy integrations.
This research work has provided the required modeling and simulation results that are crucial in
development of the full scale ‘CryoVent’
Epidemiology of the amphibian pathogen Batrachochytrium dendrobatidis, across multiple spatial scales
No full textEmerging infectious diseases are increasingly recognized as key threats to wildlife.
Batrachochytrium dendrobatidis (Bd), the causative agent of chytridiomycosis, has been
implicated in mass mortalities, population declines, and local and global extinctions of
many species of amphibians around the world. As such, it is currently the largest
infectious disease threat to biodiversity. Understanding the distribution and spatial
dynamics of Bd is crucial to predicting spread to new geographic areas, revealing the
history of infection, and developing appropriate management strategies. One of the most
striking features of Bd is the variability in outcome of infection that has been observed
within a species, among populations. By identifying and comparing differences in
variables that co-vary between populations exhibiting different infection characteristics,
we can start to disentangle the mechanisms allowing for parasite persistence and
proliferation. However, infection dynamics operate across nested levels of biological
organization: within-host processes underlie among-host processes within a population.
As such, this thesis works within the classical themes of spatial epidemiology to consider:
1) the distribution of Bd and the evidence for spatial heterogeneity in both the prevalence
and intensity of infection, and 2) the role of individual- and population-level traits in
defining infection outcome.
The research presented, identifies that Bd functions endemically within Rana pipiens
populations in Ontario. Outbreaks of chytridiomycosis are not observed, but infection
dynamics show significant interannual fluctuations related to stable geographic factors
and local climatic nuances experienced at particular host life history stages. However,
Rana pipiens also display variation in resistance to the pathogen, mediated by
thermoregulation, dispersal behaviour, and phenotypic properties. Comparisons between
host populations show variation in skin-associated bacterial communities, which may
mediate susceptibility to chytridiomycosis. These bacterial communities are found to
vary across latitude and between sites experiencing different levels of anthropogenic
disturbance. Additionally, individual level traits, such as amphibian body temperature
and body size are reported to influence bacterial community. Hence, this research
highlights the importance of considering context-dependent individual- and populationlevel
environmental heterogeneity, when attempting to predict the infection risk of Bd
Mobilité socioprofessionnelle et attachement au milieu d'origine chez les immigrants africains francophones de Sudbury (Canada)
No full textD’une approche qualitative se servant des différentes narrations structurées et conscientes des
interviewés, cette étude porte sur la compréhension de l’attachement continuel au milieu
d’origine dans les expériences de la mobilité sociale des immigrants professionnels africains
francophones installés à Sudbury.
Les résultats révèlent que la mobilité sociale des immigrants professionnels africains
francophones demeure une trajectoire socioprofessionnelle d’identification à ce qui fait leur
point définitionnel et explicatif. Quels que soient les sacrifices et les efforts consentis, leur
accomplissement socioprofessionnel ne se vit pas de façon individualiste et méritocratique,
mais solidaire au milieu d’origine. Cette étude inscrit la possible de réaliser l’ascension
socioprofessionnelle sans devenir un centrifuge, un névrosé et un déséquilibré socioculturel.
Elle justifie également que les expériences de la mobilité socioprofessionnelle internationale
marquées par la discontinuité perpétuelle des liens forts et des profonds déracinements du
milieu d’origine sont uniques et singulières à un groupe humain donné
Summary Tapes and Basic Summary Tabulations (BSTs)
No full textA presentation given to participants in Statistics Canada's Data Liberation Initiative (DLI) Ontario Training at Robarts Library, University of Toronto on December 5, 2017
The effect of doxorubicin administration on skeletal muscle
No full textSkeletal muscle (SM) is the largest organ in the human body and represents
approximately 40% of the total body weight. Maintenance of SM mass and integrity is
dependent on the delivery and removal of essential metabolic products as well as the
dynamic balance between protein synthesis and degradation. The health and maintenance
of skeletal muscle in cancer patients is of particular importance, as the significant loss of
muscular mass is an indication of cachexia, a serious life-threatening condition.
Doxorubicin (DOX) is a broad-spectrum anti-cancer chemotherapeutic and remains one of
the most widely used chemotherapeutic agents for the treatment of solid tumors and
hematological malignancies. The clinical use of DOX is limited by a well described dosedependent
and cumulative cardiotoxic side effect. The majority of DOX-related research remains focused on reducing cardiotoxicity while little is known of the effect of the drug
on SM. Therefore, the purpose of the thesis was to study the effects of DOX chemotherapy
on SM.
Study 1. The purpose of Study 1 was to examine the accumulation of doxorubicin (DOX)
and its metabolite doxorubicinol (DOXol) in skeletal muscle of the rat up to 8 days after
the administration of a 1.5 or 4.5 mg/kg i.p. dose. Subsequent to either dose, DOX and
DOXol were observed in skeletal muscle throughout the length of the experiment.
Interestingly an efflux of DOX was observed after 96 hrs, followed by an apparent reuptake
of the drug which coincided with a spike and rapid decrease of plasma DOX
concentrations. The interstitial space within the muscle did not appear to play a significant
rate limiting compartment for the uptake or release of DOX or DOXol from the tissue to the circulation. Furthermore, there was no evidence that DOX preferentially accumulated
in a specific muscle group with either dose.
Study 2. Study 2 examined intracellular and interstitial nitric oxide (NO) concentrations in
the SM following the administration of DOX. A single dose of 1.5 or 4.5 mg/kg was
administered intraperitoneally to male Sprague-Dawley rats and interstitial (IS) and
intracellular (IC) NO was quantified every 24 up to 192 hrs. post injection. There was no
significant difference in IC NO following the injection of 1.5 mg/kg DOX when compared
to control, however the administration of 4.5 mg/kg DOX resulted in lower (P<0.05)
concentrations of NO in the IC. Interestingly, a consistently higher (P<0.05) concentration
of NO in the IS was established following the administration of 1.5 mg/kg compared to
control while no significant changes in IS NO resulted from the administration of the 4.5 mg/kg dose. The fluctuation of IS and IC NO were not a result of substrate availability as
arginine concentrations remained stable throughout the experiment.
Study 3. The purpose of Study 3 was to examine the effect of DOX administration on IC,
IS and vascular concentrations of amino acids (AA) in SM of the rat up to 8 days after the
administration of a 1.5 or 4.5 mg/kg i.p. dose. Intracellular total amino acids (TAA),
essential amino acids (EAA) and branched-chain amino acids (BCAA) were significantly
increased in each muscle group analyzed, following the 1.5 and 4.5 mg/kg doses compared
to control. In the plasma, TAA were significantly increased compared to control where
greater (P>0.05) concentrations were observed following the 1.5 mg/kg dose compared to
the 4.5 mg/kg dose. Compared to control, the 1.5 mg/kg dose resulted in an increase
(P<0.05) in interstitial TAA whereas the 4.5 mg/kg resulted in a sustained decrease (P<0.05). These data represent the first concurrent investigation into the accumulation of DOX in the
IC, IS and vascular spaces as well as the resulting effects on NO and AA concentrations in
these communicating compartments. Overall, SM plays an important factor in the
availability and metabolism of DOX and the effect of DOX on SM may play a more
significant role in the therapeutic impact of DOX than previously considered. This thesis
provides a substantial foundation for future studies focused on reducing DOX-induced
skeletal muscle damage
Vibrational band structure of nanoscale phononic crystals
Get PDFThis is the peer reviewed version of the following article: R. Meyer, Vibrational band structure of nanoscale phononic crystals, Phys. Status Solidi A 213, No. 11, 29272935 (2016), which has been published in final form at https://doi.org/10.1002/pssa.201600387. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.The vibrational properties of two-dimensional phononic crystals are studied with large-scale molecular dynamics simulations and finite element method calculation. The vibrational band structure derived from the molecular dynamics simulations shows the existence of partial acoustic band gaps along the Γ-M direction. The band structure is in excellent agreement with the results from the finite element model, proving that molecular dynamics simulations can be used to study the vibrational properties of such complex systems. An analysis of the structure of the vibrational modes reveals how the acoustic modes deviate from the homogeneous bulk behaviour for shorter wavelengths and hints towards a decoupling of vibrations in the phononic crystal.Natural Sciences and Engineering Research Council of Canada (NSERC) [grant number 371446-11] , Laurentian Universit
The impact of summer break from school on children with severe autism and their parents: An Interdisciplinary Study
No full textThe purpose of this research was to investigate the effect of summer break on the academic, social, life, communication, and behaviour skills of elementary children with severe autism and to assess the recoupment of skills in the fall. Regression and recoupment were measured by testing academic Individual Education Plan (IEP) goals based on the Assessment of Basic Language and Learning Skills (ABLLS) and the Vineland Adaptive Behaviour Scale (VABS) at four time points to assess a baseline in school, the effect of summer, and the effect of returning to school, and with parent interviews. The research found that students with severe autism regressed in academic skills over the summer break, but recouped those skills within four weeks of returning to school in the fall. The other areas, rated using the VABS, did not change either during the school year baseline or over the summer break, but according to parent interviews social skills decreased and maladaptive behaviours increased. The secondary purpose of this research was to study the impact of summer break on the stress of parents of children with severe autism and to gain a qualitative understanding of the impact of summer break. Stress was assessed using the Parent Stress Index (PSI) during the school year and then again during the summer and with parent interviews. The research showed that there were increased in parent stress during the summer break. Parents reported in the interviews that summer break also had an overall negative impact on child emotions, parent relief, the child's break from the parents, and the structure of the family day, and all of these, in addition to changes to skills and behaviours, contributed to parent stress. Summer break also had a negative impact on finances and siblings and some positive effects according to interviews. Parents saw their children's disability as primarily social, requiring interventions and supports from society, while also acknowledging impairment effects. Parents suggested quality, structured, funded relief programs and workers as a solution to the negative impacts of summer break
Les effets de la loi c-36 sur les travailleuses du sexe de la rue : à la défense de leurs droits dans le nord de l’Ontario
No full textLa question de la prostitution n’a rien de nouveau. C’est une question controversée souvent
au coeur de plusieurs débats. Le débat féministe entre les prohibitionnistes et les abolitionnistes en
est un qui situe la prostitution dans un espace de libération sexuelle ou, au contraire, comme une
domination des hommes sur les femmes. Le débat juridique sur la prostitution au Canada comme
ailleurs est aussi incertain quant à une acceptation commune de son application de principes.
Certains aspects de la légalisation de la prostitution apparaissent encore difficiles sur le plan des
rapports entre les sexes bien sûr, mais aussi sur la base d’une certaine hiérarchie entre les
travailleuses du sexe elles-mêmes. Le débat entourant la loi C-36 au Canada découle d’une mise en
cause de la constitutionnalité des restrictions qui existaient relativement aux travailleuses du sexe
qui n’avaient pas le droit de communiquer et de vivre des fruits de la prostitution tel que dénoncé
par le cas Bedford contre le Canada. Or, la loi C-36 « Loi sur la protection des collectivités et des
personnes victimes d'exploitation », en criminalisant le client et ceux qui profitent des fruits de la
prostitution, ne met pas fin aux violences et cela en particulier pour les travailleuses du sexe de la
rue. La nouvelle loi isole d’avantage celles qui sont isolées par manque d’information, celles qui
vivent en région et celles qui travaillent sur la rue. C’est là du moins ce que la présente thèse montre
à l’aide de témoignages de femmes, travailleuses du sexe de la rue du nord de l’Ontario (à Sudbury
et à North Bay). Notre analyse montre une dimension intersectionnelle de la situation de la
travailleuse du sexe de la rue qui veut que dans le nord de l’Ontario. Non seulement elles sont
moins informées, plus isolées et plus à risque d’être exposées à la violence de la rue et du milieu
prostitutionnel. Nous questionnons comment cette nouvelle loi influence la vie et la réalité de ces
femmes considérées parmi les plus marginalisées d’entre toutes et qui craignent, avec la loi C-36,
d’être plus criminalisées encore. Une troisième voie entre la pensée abolitionniste et
prohibitionniste s’impose donc pour répondre aux besoins de ces travailleuses du sexe de la rue
The cortaderas zone, Pirquitas Mine, NW Argentina: an example of miocene epithermal Ag-Zn-Pb-Sn mineralization in the Andean Tin Belt
No full textThe Pirquitas mine, located in the highly elevated Puna plateau region of NW Argentina hosts Ag-rich polymetallic mineralization that defines the southern limit of the prolific Andean Tin Belt. Approximately 500 m north of its currently active open pit is the Cortaderas Zone which hosts the large Ag-Zn-rich Cortaderas Breccia whose nature and origin were previously unknown. This thesis serves as the first academic study of the Cortaderas Zone that incorporates data pertaining to its geological setting, metal distributions, breccia bodies, mineralogy, ore textures, alteration and fluid inclusions to interpret the origin of its mineralization. The results of this study suggest that the Cortaderas Zone represents the high-level and distal expression of the richly endowed hydrothermal system once present at the Pirquitas mine. Its mineralization formed in a dynamic intermediate-sulfidation epithermal system where ore formation was facilitated by transient fluctuations in confining pressure that were caused by cyclical opening and closing of the system. These insights into the formation of the Cortaderas Zone have implications for understanding the formation and subsequent modification of ores in epithermal settings globally
The effects of exogenous testosterone and mating context on men`s preferences for female facial femininity
No full textCorrelational research suggests that men show greater attraction to feminine
female faces when their testosterone (T) levels are high. Men’s preferences for feminine
faces also seem to vary as a function of relationship context (short versus long-term).
However, the relationship between T and preferences for female facial femininity has yet
to be tested experimentally. This thesis examined the causal role of T in modulating
preferences for facial femininity across both short and long-term mating contexts, using
two separate experiments. Results of Experiment 1 (within-subject design, n = 24)
showed that participants significantly preferred feminized versus masculinized versions
of women’s faces. Further, participants showed a stronger preference for feminine female
faces in the short- versus the long-term context after they received T, but not after they
received placebo. Post-hoc analyses suggest that this effect was driven by a lower
preference for feminine faces in the long-term context when on T relative to placebo.
Results from Experiment 2 (between-subject design, n = 93) were highly consistent with
those of Experiment 1: men demonstrated a significant preference for feminized female
faces in the short- versus the long-term context after T, but not after placebo
administration, and this effect was driven by lower preferences for feminine faces in the
long-term context when on T relative to placebo. Collectively, these findings provide the
first causal evidence that T modulates men’s preferences for facial femininity as a
function of mating context