Minh tue Do - Academia.edu (original) (raw)
Papers by Minh tue Do
Accidents increase during the first rain after a long dry period. This trend is due to the accumu... more Accidents increase during the first rain after a long dry period. This trend is due to the accumulation of fine particles originated from different sources such as atmosphere, road and tires debris, fuel emissions, etc. These particles accumulate on the road surface during a long dry period and induce a friction loss between the tire and the road surface. In this paper, we investigate the action of the particles during a dry period using two approaches developed in tribology: the third body approach, particularly the mass analysis to understand the particles flows at the tire/road interface; and the dry lubrication theories developed for powders (as molybdenum disulfide MoS2 ) to understand and model the friction. Experiments are conducted in laboratory to understand and model this phenomenon. Experimental protocol allows simulating the particles’ build up process on the road surface. The specimen surface, representative of a road surface, includes a microtexture scale, representing...
Aircraft braking performance depends strongly on runway surfaceconditions which can be severely d... more Aircraft braking performance depends strongly on runway surfaceconditions which can be severely degraded under adverse weather. Runway surface conditions are commonly characterized byfriction measuring devices. To provide aircraft pilots with relevant information assisting them in landing or take-off operations, friction measurements must be reliably related to aircraft braking coefficient. However, friction results are highly scaledependant (in terms of speed, mass, tire dimension and pressure, etc.) and differ between friction measuring devices and aircraft. This paper presents a method aiming at solving the scale effect, and making more reliable the prediction of aircraft braking coefficient from ground friction measurements. Works are based on the socalled ESDU model which is now used as a reference. The aim is to adjust friction coefficient – using the model – to aircraft characteristics such as speed, mass and tire pressure. The approach is applied to the IMAG friction measuri...
L'article presente une etude en laboratoire visant a reproduire les conditions de contaminati... more L'article presente une etude en laboratoire visant a reproduire les conditions de contamination par des particules fines d'une surface de chaussee. Un protocole experimental a ete developpe pour simuler le depot des particules sur un echantillon de chaussee, leur lessivage par l'eau de pluie ainsi que mesurer le frottement sur la surface contaminee. L'evolution du coefficient de frottement est comparee a celle de la masse des particules presentes sur la surface de l'echantillon. Des observations visuelles mettent en evidence le piegeage des particules par des creux de surface. Un modele simple, integrant la fraction de surface recouverte de particules, permet de reproduire les observations experimentales en condition seche.
International Journal of Environmental Research and Public Health, 2018
Although radon is a well-established contributor to lung cancer mortality among uranium miners, t... more Although radon is a well-established contributor to lung cancer mortality among uranium miners, the effects of radon decay products on different histopathologies of lung carcinoma are not well established. Using a retrospective cohort design, this study aims to examine the risks of lung cancer by histological subtypes associated with exposure to radon decay products among the Ontario Uranium Miners cohort. Cases were stratified by histological groups, and associated risks were estimated for cumulative radon exposure after adjustment for attained age and calendar period. Between 1969 and 2005, 1274 incident cases of primary lung cancer were identified. Of these, 1256 diagnoses (99%) contained information on histology. Squamous cell carcinoma was most common (31%), followed by adenocarcinoma (20%), large cells (18%), small cell lung carcinoma (14%), and other or unspecified cell types (17%). Of the histological sub-groups, small cell lung carcinoma had the strongest association with c...
Health promotion and chronic disease prevention in Canada : research, policy and practice, 2018
The opioid epidemic is currently a major public health problem in Canada. As such, knowledge of u... more The opioid epidemic is currently a major public health problem in Canada. As such, knowledge of upstream risk factors associated with opioid use is needed to inform injury prevention, health promotion and harm reduction efforts. We analyzed data extracted from 11 pediatric and 6 general hospital emergency departments (EDs) as part of the electronic Canadian Hospitals Injury Reporting and Prevention Program (eCHIRPP) from March 2011 to June 2017. We identified suspected opioid-related injuries using search strings and manually verified them. We computed age-adjusted and sex-stratified proportionate injury ratios (PIRs) and 95% confidence intervals (CIs) to compare opioid-related injuries to all injuries in eCHIRPP. Negative binomial regression was used to determine trends over time. We conducted qualitative analyses of narratives to identify common themes across life stages. Between March 2011 and June 2017, 583 suspected opioid-related poisoning/ injury cases were identified from eC...
The European respiratory journal, 2018
Perinatal exposure to ambient air pollution has been associated with childhood asthma incidence, ... more Perinatal exposure to ambient air pollution has been associated with childhood asthma incidence, however, less is known regarding the potential effect modifiers in this association. We examined whether maternal and infant characteristics modified the association between perinatal exposure to air pollution and development of childhood asthma.761 172 births occurring between 2006 and 2012 were identified in the province of Ontario, Canada. Associations between exposure to ambient air pollutants and childhood asthma incidence (up to age 6) were estimated using Cox regression models.110,981 children with asthma were identified. In models adjusted for postnatal exposures, second trimester exposures to particulate matter with a diameter ≤2.5 μm (PM) (Hazard Ratio (HR) per interquartile (IQR) increase=1.07, 95% CI: 1.06-1.09) and nitrogen dioxide (NO) (HR per IQR increase=1.06, 95% CI: 1.03-1.08) were associated with childhood asthma development. Enhanced impacts were found among children ...
Journal of Traffic and Transportation Engineering, 2014
Most of past researches on the skid resistance/road wetness relationship deal with thick water de... more Most of past researches on the skid resistance/road wetness relationship deal with thick water depths (> 1 mm). Questions remain as to the variation of skid resistance with thin water films and the transition between the dry state and the so-called "damp" or "humid" state at which the skid resistance drop can be as high as 30%-40%. This paper deals with a theoretical and experimental assessment of the friction-water depth relationship. The main objective is to estimate local water depths trapped between the tire and the road asperities and to define a so-called "critical" water depth which can be used to detect risky situations for road users. Tests are performed in laboratory. It was found that the friction-water depth curves have an inverseS shape and present an initial constant-friction part before decreasing to a minimum value. A "critical" water depth, defined as the water depth above which the friction coefficient collapses significantly, is determined from observed friction-water depth curves. Influence of test speed and road surface texture on critical water depth is discussed.
In this paper, laboratory test methods tempting at reproducing phenomena affecting pavement skid ... more In this paper, laboratory test methods tempting at reproducing phenomena affecting pavement skid resistance evolution are presented. Polishing tests using Wehner/Schulze machine can simulate polishing induced by traffic as well as the binder removal phase (typical for bituminous asphalt concrete). Binder ageing effect, responsible for friction increase at early age, can be reproduced by weatherometer; equivalence between accelerated (in day) and natural (in month) ageing times is established. With respect to seasonal variations, simple test was developed to asses the effect of pollutant presence, in addition to temperature effect. Physical model was developed. The most innovative point of this model is that it incorporates the binder-removal phase and mainly the climate effect, both responsible for the friction increase at early age, existing models reproducing only polishing effect. The model can be calibrated my means of developed laboratory tests and used as prediction tool. Comp...
Accidents increase during the first rain after a long dry period. This trend is due to the accumu... more Accidents increase during the first rain after a long dry period. This trend is due to the accumulation of fine particles originated from different sources such as atmosphere, road and tires debris, fuel emissions, etc. These particles accumulate on the road surface during a long dry period and induce a friction loss between the tire and the road surface. In this paper, we investigate the action of the particles during a dry period using two approaches developed in tribology: the third body approach, particularly the mass analysis to understand the particles flows at the tire/road interface; and the dry lubrication theories developed for powders (as molybdenum disulfide MoS2 ) to understand and model the friction. Experiments are conducted in laboratory to understand and model this phenomenon. Experimental protocol allows simulating the particles’ build up process on the road surface. The specimen surface, representative of a road surface, includes a microtexture scale, representing...
Aircraft braking performance depends strongly on runway surfaceconditions which can be severely d... more Aircraft braking performance depends strongly on runway surfaceconditions which can be severely degraded under adverse weather. Runway surface conditions are commonly characterized byfriction measuring devices. To provide aircraft pilots with relevant information assisting them in landing or take-off operations, friction measurements must be reliably related to aircraft braking coefficient. However, friction results are highly scaledependant (in terms of speed, mass, tire dimension and pressure, etc.) and differ between friction measuring devices and aircraft. This paper presents a method aiming at solving the scale effect, and making more reliable the prediction of aircraft braking coefficient from ground friction measurements. Works are based on the socalled ESDU model which is now used as a reference. The aim is to adjust friction coefficient – using the model – to aircraft characteristics such as speed, mass and tire pressure. The approach is applied to the IMAG friction measuri...
L'article presente une etude en laboratoire visant a reproduire les conditions de contaminati... more L'article presente une etude en laboratoire visant a reproduire les conditions de contamination par des particules fines d'une surface de chaussee. Un protocole experimental a ete developpe pour simuler le depot des particules sur un echantillon de chaussee, leur lessivage par l'eau de pluie ainsi que mesurer le frottement sur la surface contaminee. L'evolution du coefficient de frottement est comparee a celle de la masse des particules presentes sur la surface de l'echantillon. Des observations visuelles mettent en evidence le piegeage des particules par des creux de surface. Un modele simple, integrant la fraction de surface recouverte de particules, permet de reproduire les observations experimentales en condition seche.
International Journal of Environmental Research and Public Health, 2018
Although radon is a well-established contributor to lung cancer mortality among uranium miners, t... more Although radon is a well-established contributor to lung cancer mortality among uranium miners, the effects of radon decay products on different histopathologies of lung carcinoma are not well established. Using a retrospective cohort design, this study aims to examine the risks of lung cancer by histological subtypes associated with exposure to radon decay products among the Ontario Uranium Miners cohort. Cases were stratified by histological groups, and associated risks were estimated for cumulative radon exposure after adjustment for attained age and calendar period. Between 1969 and 2005, 1274 incident cases of primary lung cancer were identified. Of these, 1256 diagnoses (99%) contained information on histology. Squamous cell carcinoma was most common (31%), followed by adenocarcinoma (20%), large cells (18%), small cell lung carcinoma (14%), and other or unspecified cell types (17%). Of the histological sub-groups, small cell lung carcinoma had the strongest association with c...
Health promotion and chronic disease prevention in Canada : research, policy and practice, 2018
The opioid epidemic is currently a major public health problem in Canada. As such, knowledge of u... more The opioid epidemic is currently a major public health problem in Canada. As such, knowledge of upstream risk factors associated with opioid use is needed to inform injury prevention, health promotion and harm reduction efforts. We analyzed data extracted from 11 pediatric and 6 general hospital emergency departments (EDs) as part of the electronic Canadian Hospitals Injury Reporting and Prevention Program (eCHIRPP) from March 2011 to June 2017. We identified suspected opioid-related injuries using search strings and manually verified them. We computed age-adjusted and sex-stratified proportionate injury ratios (PIRs) and 95% confidence intervals (CIs) to compare opioid-related injuries to all injuries in eCHIRPP. Negative binomial regression was used to determine trends over time. We conducted qualitative analyses of narratives to identify common themes across life stages. Between March 2011 and June 2017, 583 suspected opioid-related poisoning/ injury cases were identified from eC...
The European respiratory journal, 2018
Perinatal exposure to ambient air pollution has been associated with childhood asthma incidence, ... more Perinatal exposure to ambient air pollution has been associated with childhood asthma incidence, however, less is known regarding the potential effect modifiers in this association. We examined whether maternal and infant characteristics modified the association between perinatal exposure to air pollution and development of childhood asthma.761 172 births occurring between 2006 and 2012 were identified in the province of Ontario, Canada. Associations between exposure to ambient air pollutants and childhood asthma incidence (up to age 6) were estimated using Cox regression models.110,981 children with asthma were identified. In models adjusted for postnatal exposures, second trimester exposures to particulate matter with a diameter ≤2.5 μm (PM) (Hazard Ratio (HR) per interquartile (IQR) increase=1.07, 95% CI: 1.06-1.09) and nitrogen dioxide (NO) (HR per IQR increase=1.06, 95% CI: 1.03-1.08) were associated with childhood asthma development. Enhanced impacts were found among children ...
Journal of Traffic and Transportation Engineering, 2014
Most of past researches on the skid resistance/road wetness relationship deal with thick water de... more Most of past researches on the skid resistance/road wetness relationship deal with thick water depths (> 1 mm). Questions remain as to the variation of skid resistance with thin water films and the transition between the dry state and the so-called "damp" or "humid" state at which the skid resistance drop can be as high as 30%-40%. This paper deals with a theoretical and experimental assessment of the friction-water depth relationship. The main objective is to estimate local water depths trapped between the tire and the road asperities and to define a so-called "critical" water depth which can be used to detect risky situations for road users. Tests are performed in laboratory. It was found that the friction-water depth curves have an inverseS shape and present an initial constant-friction part before decreasing to a minimum value. A "critical" water depth, defined as the water depth above which the friction coefficient collapses significantly, is determined from observed friction-water depth curves. Influence of test speed and road surface texture on critical water depth is discussed.
In this paper, laboratory test methods tempting at reproducing phenomena affecting pavement skid ... more In this paper, laboratory test methods tempting at reproducing phenomena affecting pavement skid resistance evolution are presented. Polishing tests using Wehner/Schulze machine can simulate polishing induced by traffic as well as the binder removal phase (typical for bituminous asphalt concrete). Binder ageing effect, responsible for friction increase at early age, can be reproduced by weatherometer; equivalence between accelerated (in day) and natural (in month) ageing times is established. With respect to seasonal variations, simple test was developed to asses the effect of pollutant presence, in addition to temperature effect. Physical model was developed. The most innovative point of this model is that it incorporates the binder-removal phase and mainly the climate effect, both responsible for the friction increase at early age, existing models reproducing only polishing effect. The model can be calibrated my means of developed laboratory tests and used as prediction tool. Comp...