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Measuring and modelling human response to foot-transmitted vibration exposure
Get PDFFoot-transmitted vibration (FTV) occurs when a worker is exposed to vibration through the feet
and can occur when operating vibrating equipment such as bolters, jumbo drills, or crushers, or
standing to operate mobile equipment such as locomotives and forklifts. Exposure to FTV has
been linked to the development of vibration-induced white feet, a vascular disorder with reduced
circulation to the toes causing blanching. Vibration research has been focused on whole-body
vibration (WBV) and hand-arm vibration, with FTV being lumped in to standing WBV. This
research includes, but is not limited to, resonant frequency identification, development of
international standards governing safe exposure limits, personal protective equipment design, and
model development. It is the intention of this research to initiate research specifically for FTV.
The first step to preventing harmful exposure is to identify the resonant frequencies at
different anatomical locations on the foot (Objective 1). The resonance of 24 anatomical
locations on the foot was identified for 21 participants, where the most notable differences in the
average peak frequency occurred between the toes (range: 99-147Hz), midfoot (range: 51-84Hz),
and ankle (range: 16-39Hz).
As workers do not normally stand in a completely natural position, it was equally
important to measure how altering the location of the centre of pressure (COP) changes
resonance and the transmissibility of vibration through the foot (Objective 2). The resonance at
the same 24 anatomical locations was identified when the COP was pushed forward (towards
toes) and backward (towards heels). Generally, resonance at the measurement location increased
when the COP was concentrated to a particular portion of the foot.
The third objective of this research was to reduce the measurements at 24 anatomical
locations, from the first two objectives, down to a representative subset (Objective 3). Multiple
correspondence analysis was conducted on the peak transmissibility magnitude in order to assess
structure displacement leading to increases in potential injury risk. Transmissibility results were
analysed based on two magnitude thresholds: at 2.0 indicating 100% amplification of the input
signal, and at 2.5 indicating 150% amplification. Results indicate that transmissibility
measurements at the nail bed of first phalange, head of first metatarsal, head of second
metatarsal, and the lateral malleolus may be sufficient to effectively measure foot-transmitted
vibration when participants changed their COP location from natural, forward and backward.
Then a K-means analysis was conducted to minimize the anatomical locations necessary
to capture the transmissibility response from 10 to 200 Hz, and using the reduced locations, a
lumped-parameter model was designed and validated (Objective 4). Three locations (the nail of
the big toe, the third metatarsal, and the lateral malleolus) were found to be sufficient for
summarizing FTV transmissibility modulus. A three segment, four degrees-of-freedom lumpedparameter model of the foot-ankle system (FAS) was designed to model the transmissibility
response at three locations when exposed to vertical vibration from 10 to 60 Hz. Reasonable
results were found at the ankle, midfoot, and toes in the natural standing position and forward
COP. However, when the COP is backward, the model does not sufficiently capture the
transmissibility response at the ankle.
Determining the resonant frequencies of the FAS is important for the prevention of
vibration-induced injury. Resonance needs to be incorporated into the design of equipment, tools
(e.g. anti-vibration drills, isolated platforms), and personal protective equipment (e.g. antivibration insoles or boots) can be modified to reduce vibration at the frequencies where tissue
resonance occurs. These findings could also inform the development of new international
standards for measuring/reducing exposure to FTV
Understanding the characteristics and consequences of the Toxic Sports Staff Member (TSSM) through the stories of male soccer players
Get PDFThe current study examined the characteristics and consequences of the toxic sports staff
member (TSSM) through the stories of elite-level male soccer players. The stories of seven
participants were collected through a conversational interview that followed an art-based activity
(i.e., mandala drawings) and were analyzed using an inductive thematic analysis. Six themes
related to the characteristics of the TSSM were introduced, they were: passionate, insecure,
controlling, rigid to own viewpoints, poor communicator, and selfish. Further, six consequences
of the TSSM were introduced, they were: increased negative and decreased positive affective
states, lack of player development, creation of a destructive environment, increased team unity,
decreased performance, and loss of players. Understanding the characteristics and consequences
of the TSSM provides a starting point for understanding negative staff roles within sports.
Further, sporting organizations may use the results as a way of identifying and controlling for
negative roles within their team
Immigrant landscapes: architecture in the age of migration
No full textNorth American cities are being transformed both architecturally and
culturally by migration, yet their infrastructure is often too standardized and
homogenous to accommodate diversity. Using the City of Sudbury as an example,
this thesis imagines an Immigration Support Centre that repositions the relationship
between the people, ethnicity and place.
Rather than assuming migration only happens in bigger centres this
thesis addresses the desire for a local community to attract newcomers to a
Northern city. This brings to light the need to provide cities with inclusive designs
that can welcome. Now more than ever, architects and designers are faced with
the problem of designing for diverse people. What if, instead of favoring spatial
homogenization and cultural assimilation, we start from the premise of cultural
diversity in architecture as crucial to humanity? Although this thesis aims to provide
an architectural project for Sudbury, it is intended to be a framework of research that
may be applied to other cities regardless of size
Exploring the benefits of delivering arts-based mindfulness groups and methods in school settings
No full textChildren and youth with significant mental health challenges often experience academic
and social-emotional difficulties at school. Early intervention is linked to improved mental health
and academic outcomes in school-aged youth. School boards across Ontario are adopting a
universal mental health promotion model where group programming is delivered to full
classrooms as a way to enhance wellness in schools. For my advanced practicum, I implemented
the Holistic Arts-Based Program (HAP) within the Rainbow District School Board with support
from various social workers, educators, and educational assistants. HAP is a group program that
teaches youth mindfulness skills and concepts through arts-based and experiential methods. The
HAP program is an enjoyable and engaging way to teach mindfulness to youth. My goal was to
explore the benefits of delivering arts-based mindfulness groups and methods in school settings.
HAP proved to be an excellent program to implement in schools as a way of fostering student
resilience, teaching coping skills, and building self-esteem, and self-awareness. Through artsbased and experiential methods, students can learn a variety of tools and strategies that will
enhance their wellbeing. Delivering HAP in various schools allowed students to build
connections with peers and their teachers. HAP also promoted inclusion, diversity, empathy, and
respect for others. Art-based methods enabled students to express themselves and learn about one
another in a creative, meaningful, and interactive way. School administration should consider
implementing arts-based mindfulness groups in classrooms when selecting universal promotion
programs for their schools. Schools are the ideal place to deliver effective and strengths-based
group work.Master of Social Work (MSW) Progra
Microbial community and C cycling across permafrost peatlands in the Hudson Bay Lowlands: feedbacks to in-situ degradation and simulated warming
No full textPeatlands in the Hudson Bay Lowlands (HBL) constitute a sensitive and globally
significant store of carbon, estimated at approximately 30 Pg, where in the northern portion of
the HBL a significant amount of this carbon is stored in permafrost. Particularly, near-surface
permafrost in the HBL occurs as palsas which are omnipresent in the HBL. However, permafrost
degradation in the HBL is proceeding at an accelerated pace as changing sea-ice dynamics in
Hudson Bay amplify the regional effects of climate change. The degradation of permafrost leads
to decomposition of organic carbon, which produces two important greenhouse gases; carbon
dioxide (CO2) and methane (CH4). Under the context of climate change and degrading
permafrost conditions in the HBL, this research investigated the microbially mediated
production of CO2 and CH4 from palsas and adjacent thermokarst features from the Hudson Bay
Lowlands, and the effects of palsa evolution on these processes. In August of 2017, cores of
active layer, permafrost, and thermokarst were collected from five replicate palsas in the
continuous zone of permafrost within a 150 km2 watershed selected for monitoring by the
Ontario Ministry of Natural Resources and Forestry. Short-term aerobic incubations (7 days) at
field moisture conditions were used to assess methane production and consumption, and longterm (225 days) anaerobic incubations were used to assess methane production. Peat
chemistry was characterized through elemental analysis, including peat substrate chemistry
through the use of Fourier-Transform Infrared (FTIR) Spectroscopy. Finally, microbial
communities from samples pre- and post-incubation were characterized via Illumina highthroughput sequencing for 16s rRNA. This study finds that active layer samples are capable of
oxidizing CH4 under field conditions, whereas permafrost samples generally produced CH4. Under anaerobic conditions, thermokarst samples are much more prolific producers of CH4 in
comparison to permafrost and active layer samples. This study suggests that it is peat chemistry
and changes in vegetation associated with the evolution of palsas responsible for increased
production of CH4 from thermokarst. This is the result of combined physical and chemical
conditions both conducive to methanogenesis, where differing peat chemistry increases the
availability of substrates utilized by methanogens, as well as increased zones of anaerobiosis.
This research highlights the need for permafrost carbon models to include degradation of
palsas via thermokarst encroachment, as this study demonstrates that it has important
implications for the production and release of CH4
Surface modification of biodegradable magnesium implant materials for controlled biodegradation
No full textMagnesium and its alloys are promising candidates to be employed as a new generation
of biodegradable metals in orthopaedic applications. However, the rapid degradation rate of
magnesium alloys in the physiological environment has prevented their widespread application
in medicine. The main objective of this thesis was to develop surface modification strategies that
control the degradation rate of magnesium alloys in physiological environments and to provide
an accurate assessment and evaluation of their biocompatibility in vitro. The overall thesis is
composed of three individual projects.
The first project was to develop an accurate method to test the in vitro biocompatibility of
magnesium alloys. In this study, the CyQUANT assay was used to quantitatively evaluate the in
vitro biocompatibility of Mg AZ31 alloy by both direct and indirect methods. The results
demonstrated that the CyQUANT assay provides a more complete assessment of the overall in
vitro biocompatibility of biodegradable metals by combining both direct and indirect analyses. In the second project, a multilayer coating consisting of a sol-gel silica layer followed by
a mesoporous silica layer and finally a layer of calcium phosphate was developed. Surface
characterization showed that a uniform and stable multilayer coating was successfully deposited
on the Mg AZ31 alloy. In vitro characterization of the coatings confirmed this surface
modification strategy significantly decreases the degradation rate of the magnesium alloy and
that it is not cytotoxic.
Superhydrophobic surfaces decrease the corrosion rate of magnesium alloys, however,
cell adhesion is inhibited. In the third project, a superhydrophobic magnesium alloy surface was
modified with the cell adhesive molecule, MAPTrix-F-RGD and the influence of this surface modification on cell adhesion was studied. The results demonstrate that although the MAPTrixF-RGD molecule was successfully immobilized to the superhydrophobic magnesium alloy
surface, cell adhesion was not improved. The complex surface topography of the
superhydrophobic Mg AZ31 surface may be responsible for the observed cell behavior.
This thesis demonstrates that surface modification can be used to simultaneously control
both the biodegradation rate and the biocompatibility of magnesium and its alloys, making these
materials promising candidates for orthopaedic applications. In addition, it has been
demonstrated that cell quantification assays based on the fluorescence of cyanine dyes are an
excellent method for in vitro testing of these materials in direct contact with cells
Gravity data acquisition and potential-field data modelling along Metal Earth's Chibougamau transect using geophysical and geological constraints
No full textThe Metal Earth (ME) project aims to understand the underlying geological mechanisms that
differentiate mineral endowments in Precambrian greenstone belts of the Canadian Shield. The
ME project acquires and collates various geological and geophysical data along 13 transects to
create valid models of subsurface features in order to identify components that contribute to the
mineralization processes that result in mineral endowment.
In this thesis, gravity observation along ~128 line kilometers in the Chibougamau transect is
considered. The acquired data were checked for quality, processed to calculate the complete
Bouguer anomaly and combined with existing gravity data provided by the Geological Survey of
Canada.
Gravity and compiled magnetic data were forward modelled along four sections and constrained
by surficial geological observations, seismic sections, and petrophysical properties to estimate
and improve the geometry and depth of plutonic bodies, and identifying the subsurface features
such as dykes and faults. These improvements will help others to identify components that
contribute to mineralising processes
Prediction of heart disease dataset using hybrid optimization and machine learning techniques
No full textThe traditional methods of cancer diagnosis and cancer-type recognition have quite a large number
of limitations in terms of speed and accuracy. However, recent studies on cancer diagnosis are
focused on molecular level identification so as to improve the capability of diagnosis process.
Several recent research studies have used data mining techniques, machine learning algorithms and
statistical methods to study the issue of cancer classification to achieve an effective analysis on gene
expression profiles. The process has been supported by data mining and machine learning techniques
such that a smart combination of various algorithms and techniques can generate comparatively
efficient and reliable output. In this thesis, four distinct classification methods are used – Support
Vector Machine (SVM) (SVM with Gaussian Kernel and SVM with Radial Basis Kernel), K –
Nearest Neighbor, Naïve Bayes and Random Forest to study the accuracy of prediction using heart
disease dataset. The models were trained using different training-testing ratios to get the optimal
results. Three optimization techniques were used to further improve the prediction accuracy of heart
disease. Various performance parameters including accuracy and area under the ROC curve (AUC)
were computed to test the optimization algorithms, Grey Wolf Optimization (GWO), Oppositional
Grey Wolf Optimizer (OGWO) and Hybrid Particle Swarm Optimization with Grey Wolf Optimizer
(HPSOGWO) with the four classifiers to obtain the best optimized classifier for the heart disease
datasets. The datasets used in this thesis are of heart disease taken from three different locations:
Cleveland, Hungarian and Switzerland. The results show that best accuracy was achieved by using
the hybrid PSO with GWO (HPSOGWO) in Switzerland (with Random Forest) and Hungarian (with
KNN) datasets whereas GWO gave the highest accuracy for the Cleveland (with Random Forest)
dataset with the HPSOGWO very close in accuracy to GWO
Feedback management of pedagogical inspections of preservice sport and physical education teachers in INJEPS - Republic of Benin
No full textLe but de cette recherche est d’analyser le système d’encadrement pédagogique des étudiants en Sciences et
Techniques des Activités Physiques et Sportives en formation initiale à l’Institut National de la Jeunesse, de l’Education Physique et des Sports (INJEPS) lors de leurs stages dans des établissements d’enseignement secondaire. À partir d’une grille de lecture composée du modèle systémique du processus d’intervention de Dunkin et Biddle (1974) et celui de Chevallard (1992), cette étude problématise d’une part le fait didactique à partir des variables de contexte, de programme, de processus et de produit et, d’autre part, du concept de praxéologie. Par ailleurs, elle cherche aussi à comprendre les variables déterminantes au processus de supervision pédagogique et la manière dont l’INJEPS gère les feedbacks produits par les
superviseurs de l’INJEPS et de la Direction de l’Inspection Pédagogique.
Il ressort, de l’analyse des résultats des investigations, que les superviseurs des deux institutions mettent essentiellement l’accent sur les variables de contexte, de processus et de produit lors de l’encadrement pédagogique des stagiaires de 3ème, 4ème et 5ème année, alors que les variables de programme aussi sont pris en compte en 1ère et 2ème année. A l’issue des supervisions seules les notes de stage produites par les rapports pédagogiques des superviseurs sont prises en compte par l’administration lors des évaluations partielles et terminales des étudiants. Aucun traitement didactique des contenus des
feedbacks n’est fait dans la perspective d’améliorer la formation pédagogique des futurs enseignants
Rural restorative agritecture: the case of Grassridge Farmstead in Brant County
No full textThis thesis investigates the relationship between architecture and agriculture, considering
that the two disciplines have frequently been unrelated. The emerging field called Rural
Design (Thorbeck 2012, Stringer 2018) shows the potential of the teachings of Restorative
Agritecture for reimagining the relation between agriculture and architecture. More
particularly this thesis explores restorative principles, and strategies of placemaking, to
revive abandoned farmsteads and create a sense of community, considering the case of
Grassridge Farmstead, situated in Brant County, Ontario. Combining an investigation on
the process of rural design with reflection on a collection of personal experiences, and a
careful material culture analysis of the existing site and its artifacts, three strategies were
developed – repair, reinvention, restorative – to design a cooperative community
farmstead