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Determining the feasibility of a real-time geophysical magnetic and electric measurement system for monitoring strain underground
Get PDFIn deep mining environments, rockbursts can occur in areas of high stress. The unpredictable nature, and sometimes fatal consequences of the rockbursts, makes identifying increases in stress
that occur prior to failure events, important for mine safety. The piezoelectric, electrokinetic, and seismo-electric/magnetic effects result in rocks that are stressed emitting electric and
magnetic fields that can potentially be measured in (or close to) a rock mass. Electric, magnetic and seismic data were collected during a four-day period at Coleman Mine, Sudbury, Ontario,
and later analysed. No signals due to strain were evident in the magnetic or electric data, so a more careful three-part experiment was proposed to see if strain related signals could be identified in magnetic data. In the first part of the experiment thirty-two rocks were stressed
until failure. Measurable magnetic signals associated with audible cracking sounds were found for most rock samples, as well as consistent signals across all samples prior to failure. The implementation of real-time monitoring of these signals has the potential to significantly improve
deep mine safety by mapping the evolution of strain underground and potentially indicating areas susceptible to failure
Mine schedule optimization with geotechnical constraints
Get PDFIf a mining project consists of n stoping activities these can be scheduled in n! ways according to
the duration between the activities and their precedence. Mine schedule optimization
manipulates the precedence relationships and the duration of the mining activities in order to
maximize the Net Present Value (NPV). However, unexpected instabilities may impede or
disrupt the schedule and thus reduce the profitability and so geotechnical aspects of the operation
need to be taken into account.
The mine schedule optimization software considered in this work is the so-called Schedule
Optimization Tool (SOT). This thesis reports the work for development of new geomechanical
constraints for any mine scheduling tool to find the safest and the most profitable schedule,
exemplified within the SOT framework.
The core hypothesis of this research is that there is a time-dependent aspect of the rock behaviour
that leads to instability, a consequence of dependence of geotechnical instability upon the
sequence and duration between stoping activities. There is evidence presented in this work that
supports this hypothesis.
An automated procedure for timely and computationally efficient calculations of the instability
metrics is presented. This can be applied to evaluate the geomechanical stability of any of the n!
schedules for excavating n stopes or applied to evaluate geomechanical stability of schedules
arising in the schedule optimization process. However, in practice, the number of feasible
schedules is much less than n! due to the precedence constraints. The approach starts with
computing n elastic stress fields induced after excavating each individual stope independently
within an identical computational domain using Compute3D. The stress-time series of each
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and/or every sequence of stoping are generated through superimposition of these pre-computed
stress fields, and the time stamps of blasting for excavation are allocated corresponding to the
stoping timetable. Different blasts are allowed to be timetabled at the same time. By means of
Hooke’s law and the 3D Kelvin-Voigt creep model the elastic strain time series and the
viscoelastic strain time series are produced for the stress-time series. Based on the Mohr-
Coulomb Failure criterion three (in)stability indicators are defined:
i. ‘Strength Factor’ to evaluate state of stress at each stage of each schedule as a proportion
of is strength
ii. ‘Strainth Factor’ to evaluate state of elastic strain at each stage of each schedule as a
proportion of a limiting ‘rupture’ strain
iii. ‘Viscoelastic-strainth Factor’ to evaluate state of viscoelastic strain at each stage of each
schedule as a proportion of a limiting ‘rupture’ strain.
To provide a perspective of the (in)stability condition in the computational domain for all the
feasible sequences of stoping, 12 (in)stability metrics were defined and the results of each are
illustrated in the form of ‘(in)stability indicator diagrams’. The overall methodology is applied
to an example of excavating 6 open stopes.
Additionally, a methodology is theorized to evaluate the stability condition in the rock mass
surrounding the stopes for a series of stoping and backfilling schedules. The methodology is
based on pre-computing one additional stress field element for each stope, which represents the
effect of the fill loading on the rock mass. The calculations for this approach are consistent with
the time and computational efficiency of the original methodology. The computational effort
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increases to ‘2n’ pre-computed stress fields rather than ‘n’: as problem sizes double,
computational time doubles, rather than increases in polynomial or exponential time
Characterisation of CTR-17 and CTR-20, novel chalcone derivatives that inhibit tubulin polymerisation activity
No full textAgents targeting colchicine-binding sites are recognised as valuable lead
compounds in the development of new anticancer drugs. Although colchicine can
effectively inhibit cell proliferation, its use as an anticancer agent has not been
approved by the FDA due to its inherent toxicity. To develop colchicine-binding
site targeting agents with low or no toxicity, in collaboration with Rajiv Gandhi
Technical University of India, several chalcone derivatives were created and
examined. Preliminary studies at the Lee Lab identified CTR-17 and CTR-20 as
promising leads. Their anti-proliferative activities using three human breast
cancer cell lines (MDA-MB468, MDA-MB231 and MCF-7) and two matching noncancer
breast cell lines (184B5 and MCF10A) were initially determined.
Subsequently, nine other cancer cell lines were used to assess the broad
spectrum anti-proliferative effects of the CTR compounds. Data from this study
showed that CTR-17 and CTR-20 preferentially kill cancer cells 10-25 times over
non-cancer cells. Data obtained from flow cytometry, confocal microscopy and
Western blotting showed that CTR-17 induced a prolonged mitotic arrest, leading
to cancer cell death probably via apoptosis. I also found that both CTR-17 and
CTR-20 inhibited tubulin polymerisation and bound to purified tubulin fibers with a
dissociation constant of 4.58±0.95 μM and 5.09±0.49 μM, respectively. CTR-17
and CTR-20 competitively inhibited the binding of colchicine to tubulin with an
inhibitory concentration of 5.68±0.35 μM and 1.05±0.39 μM, respectively,
suggesting that the CTR compounds bind to tubulin at a site partially overlapping
the colchicine-binding site. Molecular docking studies confirmed this binding to
occur via two and one hydrogen bonds between tubulin and CTR-20 and CTRiv
17, respectively. More interestingly, CTR compounds inhibit the proliferation of
multi-drug resistant cell lines, which overexpress drug transporters involved in
the efflux of clinically available microtubule targeting agents. In addition, the CTR
compounds exhibit a synergistic relationship with paclitaxel in causing
cytotoxicity to a P-glycoprotein overexpressing cell line. Therefore, these novel
chalcone derivatives not only possess cancer-specific cell killing property but
also the ability to exhibit similar cytotoxicity to both the multi-drug sensitive and
resistant cells. Hence, CTR compounds possess substantial potential as safe
and effective anticancer drugs
LES HABILETÉS LANGAGIÈRES DES ENFANTS NÉS PRÉMATURÉS D’ÂGE SCOLAIRE AU NORD DE L’ONTARIO
No full textSeismic hazard evaluation using apparent stress ratio for mining-induced seismic events
No full textThis thesis investigates precursory trends in seismic data prior to the occurrence of large and
potentially damaging seismic events at Agnico Eagle’s LaRonde mine. A variety of sample
populations are selected to represent varying degrees of seismic hazard within a large area of
interest at LaRonde. The main factor considered for hazard assessment is the local stress
conditions within the rock mass, inferred from the apparent stress of seismic events.
An alternative means of analyzing apparent stress measurements using a relative ratio, referred to
as Apparent Stress Ratio (ASR), is presented. The use of a ratio eliminates the need for
thresholds values to define high and abnormal apparent stress. ASR values are analyzed in
reference to varying time frames, allowing for changes in stress conditions over time to be
considered. Hazard maps created using ASR and peak ASR values correspond well to areas of
elevated seismic hazard previously identified at LaRonde. For an area of interest at LaRonde,
ASR as an alarm tool possesses a success rate of 68% with a false alarm ratio of 2:1
Exploring the relationships among nursing students' anxiety in the clinical setting and select demographics.
No full textThe clinical learning experience is an essential part of nursing education that is often
anxiety provoking. Understanding the factors associated with the anxiety levels of nursing
students in clinical placements has become more complex over the years with the increasing
heterogeneity of the nursing population. Associations between student demographics and their
anxiety levels in the clinical setting have not yet been explored in the research literature. The
questions guiding this descriptive correlational study are as follows: What is the anxiety level of
students as determined by the State-Trait Anxiety Inventory (STAI)? Is there a relationship
between students’ age, gender, previous employment, and previous education and their selfperceived
anxiety levels? The framework for this study is situated cognition theory.
The data provided through the study revealed that nursing students have a higher than
average level of anxiety. The data revealed no statistical significant correlations involving age,
previous education, previous employment, and self-perceived anxiety levels. There was a
statistically significant difference between the anxiety scores of the female group and those of the male group, with males reporting higher levels of anxiety. The data provide an opportunity
for discussion and identify the need for future research and practice
Early Interventions to trauma: an examination of crisis support delivery, trauma clinician skill development, and potential applications for child welfare apprehension and placement
No full textThis advanced practicum thesis presents a Master of Social Work student’s journey
toward becoming a more skilled trauma clinician. It also serves as a forum to consider
opportunities to limit or reduce trauma potentially suffered by clients through their engagement
in my current field of social work practice, child welfare. This practicum was completed with the
Victim Crisis Unit (VCU), a division of the Ottawa Police Services. The Victim Crisis Unit is
devoted to providing emergency service provision to Ottawa residents exposed to trauma or
criminal victimization. Three primary goals were developed for this practicum experience. The
first goal was to gain, through experiential learning, the ability to practice ethically sound,
effective, Early Intervention (EI) techniques targeted at mitigating the negative effects of
victimization and trauma. The second goal was to make an overall improvement to my capacity
as a trauma clinician by developing my therapeutic presence, client-engagement, self-awareness,
and professional self-care through learning about mindfulness research and practice. My third
goal was to reflect on the combination of my research and experiential learning in order to
present a critical analysis of the potential applications of EI techniques for child welfare practice,
most specifically, how they might make the process of bringing children into care more trauma-
informed and less damaging.Master of Social Work Progra
Content analysis of the seven "Myth vs. Reality" statements from NAFTAnow.org : the importance of the application of critical discourse analysis & framing theory.
No full textNorman Fairclough and Ervin Goffman both believed that discourse could be used as weapon.
The dissertation addresses the importance of utilizing Critical Discourse Analysis and Framing
theory when consuming any information. In my analysis I will conduct a content analysis and a
systematic test of verification to verify the accuracy of the seven NAFTA "Myth vs. Reality"
statements on the official NAFTA website, NAFTAnow.org. In addition to this, I will also
critically analyze the "Myth vs. Reality Model" used to present the seven claims. The importance
of questing power and authority, to uncover hidden ideologies, is pivotal to obtaining clarity in
text. The application of systematically verifying discourse shows the true essence of information
and can expose empty claims. This is important in daily encounters with information and
essential when conducting research
Étude normative de la fréquence des types d’erreurs d’orthographe produites par des élèves retrouvées en situation démolinguistique différente – Sudbury (ON, Canada), Ville-Marie (QU, Canada) et Paris (FR, Europe).
No full textAre harmonious and obsessive passions distinct?
No full textAbstract
Passionate activities can be a source of pleasure and meaning. According to the Dualistic Model
of Passion (Vallerand et al., 2003) individuals can have either a harmonious or an obsessive
passion for an activity. Where harmonious passions provide positive emotional experience,
obsessive passions do not. Using Fredrickson’s broaden-and-build theory (2004), it was
hypothesized that harmonious passions could have cognitive benefits. By grouping individuals
(N=141, M-age=24 years, 89 women) based on their passion orientation, the roles of selfreported
optimism, social desirability, social support, attention, executive functioning, and life
quality were examined in distinguishing harmonious and obsessive passion. It was demonstrated
that harmoniously passionate individuals differed from the obsessively passionate on all
measures of attention, executive functioning, and life quality. Where obsessively passionate
individuals reported lower attention, executive functioning, and life quality, harmoniously
passionate individuals did not. Individuals who were highly passionate differed from less
passionate people on optimism. These differences correspond well to that which would be
predicted on the basis of the broaden-and-build theory. Taxometric methods were also used to
investigate the latent structure of Vallerand’s Passion questionnaire. Taxometric methods can test
whether a construct is categorical (passion being harmonious or obsessive) or dimensional (only
varying in degrees of intensity). Results from taxometric analyses (MAMBAC/MAXCOV) are
most consistent with the idea that passion exists in a continuum between its harmonious and
obsessive forms