Showing papers by "Ontario Ministry of Transportation published in 2015"
TL;DR: In this article, the evolution of the physical and mechanical properties of granite specimens from room temperature to 800°C was studied and the results indicated five phases in the variation of physical/mechanical properties with temperature: the first phase corresponds to the vaporization-escaping interval of adhered water, bound water, and structural water.
Abstract: High temperature may lead to the development of new microcracks or growth of pre-existing microcracks within granite, varying its physical and mechanical properties. Experiments were conducted to study the evolution of the physical and mechanical properties of granite specimens from room temperature to 800 °C. The specimens were heated in heating furnace and uniaxial compression tests were done using MTS servo-controlled testing machine. The results indicate five phases in the variation of physical and mechanical properties with temperature: from room temperature to 100, 100–300, 300–400, 400–600, and 600–800 °C. The first phase corresponds to the vaporization-escaping interval of adhered water, bound water, and structural water. Larger changes of physical and mechanical parameters in the temperature range of 300–600 °C, mostly 400–600 °C, are probably caused by the transition from the brittle state to plasticity (or ductility) of granite, and 400 °C may be a critical threshold of its thermal damage. These results confirm the important link among physical and mechanical properties in response to thermal treatment.
128 citations
TL;DR: A back-propagation neural network model was developed and can accurately predict drivers' lane changing behaviour for at least 1.5 s in advance, superior to the use of turn signals in predicting lane-changing behaviour.
113 citations
TL;DR: In this paper, an inventory is presented for NH3 emissions from China's agricultural fertilizer application at the city-level, and on a 1.1 km grid for croplands in 2010.
83 citations
TL;DR: PCA result showed that urban and port areas, agriculture, and atmospheric deposition were the main sources of pollutants in the bay and DIN was the main pollutant and was responsible for the eutrophication risk in Bohai Bay.
68 citations
TL;DR: A method that uses a coarse-to-fine scheme and has superior performance in the accuracy and stability of its reading identification is introduced and is applicable for reading gauges whose scale marks are either evenly or unevenly distributed.
Abstract: This study proposes an automatic reading approach for a pointer gauge based on computer vision. Moreover, the study aims to highlight the defects of the current automatic-recognition method of the pointer gauge and introduces a method that uses a coarse-to-fine scheme and has superior performance in the accuracy and stability of its reading identification. First, it uses the region growing method to locate the dial region and its center. Second, it uses an improved central projection method to determine the circular scale region under the polar coordinate system and detect the scale marks. Then, the border detection is implemented in the dial image, and the Hough transform method is used to obtain the pointer direction by means of pointer contour fitting. Finally, the reading of the gauge is obtained by comparing the location of the pointer with the scale marks. The experimental results demonstrate the effectiveness of the proposed approach. This approach is applicable for reading gauges whose scale marks are either evenly or unevenly distributed.
62 citations
TL;DR: Using a pure AlON powder synthesized by carbothermal reduction and nitridation, a bimodal particle size distribution (PSD) powder was prepared by planetary ball mill, and pressurelessly sintered at 1880°C to fabricate transparent AlON ceramics as mentioned in this paper.
55 citations
TL;DR: In this paper, a new method that combines Delphi survey, geographic information system and Monte Carlo simulation was proposed to assess regional ecological vulnerability and to quantify the uncertainty of assessing result, which illustrated the capacity of this method by using a case study in northeastern Inner Mongolia, China.
54 citations
TL;DR: In this paper, three interpolation methods (natural neighbors, cubic spline and angular distance weighting) are used to calculate grids at five different horizontal gridded resolutions ranging from 0.25° to 2.5°.
Abstract: Using daily station observations over the period 1951–2013 in a region of south-east Australia, we systematically compare how the horizontal resolution, interpolation method and order of operation in generating gridded data sets affect estimates of annual extreme indices of temperature and precipitation maxima (hottest and wettest days). Three interpolation methods (natural neighbors, cubic spline and angular distance weighting) are used to calculate grids at five different horizontal gridded resolutions ranging from 0.25° to 2.5°. In each case the order of operation in which the grid values of the hottest and wettest day are calculated is varied: either they are estimated from daily grids or from station points and then gridded. We find that the grid resolution-despite showing more regional detail at high resolution – has relatively limited effect when considering regional averages. However, the interpolation method and the order of operation can substantially influence the actual gridded values. And while the difference due to the order of operation is not substantial when using natural neighbor and cubic spline interpolation, it is particularly apparent for indices calculated from daily gridded estimates using the angular distance weighting method. As expected given the high spatial variability of precipitation fields, precipitation extremes are most sensitive to method, but temperature extremes also exhibit substantial differences. For the annual maximum values averaged over the study area, the differences may be up to 2.8 °C for temperature and 60 mm (about a factor 2) for precipitation. Differences are seen most prominently in return period estimates where a 1 in 100 year return value calculated using the angular distance weighting daily gridded method is equivalent to about a 1 in 5 year return value in most of the other methods. Despite substantial differences in the actual values of gridded extremes, analyses suggest that the impact on long-term trends and inter-annual variability is small.
52 citations
TL;DR: In this article, the effect of temperature, frequency as well as the content of tourmaline powder on the complex modulus and phase angle of bitumen was investigated by dynamic shear rheometer (DSR).
44 citations
TL;DR: In this paper, the authors investigated the energy dissipation and damage behavior of frozen loess during deformation process under triaxial compression, besides TC tests, and found that the loading stages of TLUC test curves and TC test curves almost coincided under different confining pressure conditions.
39 citations
TL;DR: Dolphin biosonar detection and its diel, lunar, seasonal and tidal patterns were examined and significant higher echolocation detections at night than during the day, in winter-spring than in summer-autumn, at high tide than at flood tide were recognized.
Abstract: A growing demand for sustainable energy has led to an increase in construction of offshore windfarms. Guishan windmill farm will be constructed in the Pearl River Estuary, China, which sustains the world's largest known population of Indo-Pacific humpback dolphins (Sousa chinensis). Dolphin conservation is an urgent issue in this region. By using passive acoustic monitoring, a baseline distribution of data on this species in the Pearl River Estuary during pre-construction period had been collected. Dolphin biosonar detection and its diel, lunar, seasonal and tidal patterns were examined using a Generalized Linear Model. Significant higher echolocation detections at night than during the day, in winter-spring than in summer-autumn, at high tide than at flood tide were recognized. Significant higher echolocation detections during the new moon were recognized at night time. The diel, lunar and seasonal patterns for the echolocation encounter duration also significantly varied. These patterns could be due to the spatial-temporal variability of dolphin prey and illumination conditions. The baseline information will be useful for driving further effective action on the conservation of this species and in facilitating later assessments of the effects of the offshore windfarm on the dolphins by comparing the baseline to post construction and post mitigation efforts.
TL;DR: In this paper, the influence of surface modifiers on the aging properties of nano-zinc oxide modified bitumen was evaluated, and the results showed that surface modifiers, such as 3-aminopropyltriethoxysilane (APTS), MTS, APT, and EPTMS, are successfully bound on the surface of nano zinc oxide.
Abstract: Nanocomposites based on bitumen and nano-zinc oxide with three surface modifiers, γ-methacryloxypropyl trimethoxy silane (MTS), 3-aminopropyltriethoxysilane (APTS), and γ-(2,3-epoxypropoxy) propytrimethoxysilane (EPTMS), have been prepared by melt blending. The influence of surface modifiers on ultraviolet (UV) aging properties of nano-zinc oxide modified bitumen was evaluated. The results show that MTS, APT, and EPTMS are successfully bound on the surface of nano-zinc oxide. The dispersion stability of nano-zinc oxide in bitumen is improved by three surface modifiers. Compared with MTS and EPTMS, APTS-nano-zinc oxide modified bitumen shows the lowest VAI values and carbonyl index after UV aging, indicating its good UV aging resistance.
TL;DR: In this article, the effects of the embedded monopile foundation on the local distributions of pore water pressure, soil stresses, and liquefaction are investigated using a three-dimensional integrated numerical model.
Abstract: Effects of the embedded monopile foundation on the local distributions of pore water pressure, soil stresses, and liquefaction are investigated in this study using a three-dimensional integrated numerical model. The model is based on a Reynolds-Averaged Navier-Stokes wave module and a fully dynamic poroelastic seabed module and has been validated with the analytical solution and experimental data. Results show that, compared to the situation without an embedded foundation, the embedded monopile foundation increases and decreases the maximum pore water pressure in the seabed around and below the foundation, respectively. The embedded monopile foundation also significantly modifies the distributions of the maximum effective soil stress around the foundation and causes a local concentration of soil stress below the two lower corners of foundation. A parametric study reveals that the effects of embedded monopile foundation on pore water pressure increase as the degrees of saturation and soil permeability decrease. The embedded monopile foundation tends to decrease the liquefaction depth around the structure, and this effect is relatively more obvious for greater degrees of saturation, greater soil permeabilities, and smaller wave heights.
TL;DR: A space-time network- based modeling framework for integrated fixed and mobile sensor networks, in order to provide a rapid and systematic road traffic monitoring mechanism for emerging small Unmanned Aerial Vehicles.
Abstract: It is essential for transportation management centers to equip and manage a network of fixed and mobile sensors in order to quickly detect traffic incidents and further monitor the related impact areas, especially for high-impact accidents with dramatic traffic congestion propagation. As emerging small Unmanned Aerial Vehicles (UAVs) start to have a more flexible regulation environment, it is critically important to fully explore the potential for of using UAVs for monitoring recurring and non-recurring traffic conditions and special events on transportation networks. This paper presents a space-time network- based modeling framework for integrated fixed and mobile sensor networks, in order to provide a rapid and systematic road traffic monitoring mechanism. By constructing a discretized space-time network to characterize not only the speed for UAVs but also the time-sensitive impact areas of traffic congestion, we formulate the problem as a linear integer programming model to minimize the detection delay cost and operational cost, subject to feasible flying route constraints. A Lagrangian relaxation solution framework is developed to decompose the original complex problem into a series of computationally efficient time-dependent and least cost path finding sub-problems. Several examples are used to demonstrate the results of proposed models in UAVs’ route planning for small and medium-scale networks.
TL;DR: In this article, a simplified analysis method based on effective width was proposed to account for the shear-lag effect of composite decks, which would greatly assist in design analysis as it is easy to use in a general beam element model.
TL;DR: In this paper, the physics of the breach erosion process, particularly, the breach initiation process in over-topped landslide dams, were studied. But the authors only considered homogeneous landslide dams and did not consider the effects of the seepage during the breach development, the permeability characteristics of the dam materials are also taken into consideration.
Abstract: The present paper studies the physics of the breach erosion process, particularly, the breach initiation process in over-topped landslide dams. Due to great complexities involved, only homogeneous landslide dams are considered. The flume experiments of dam overtopping are conducted to study the breach growth process. And in order to reveal the effects of the seepage during the breach development, the permeability characteristics of the dam materials are also taken into consideration. With the experimental observation, the details of the breach growth are examined, and the whole breach process could be distinguished into five stages, i.e., Stage I, the seepage erosion, Stage II, the formation of the initial breach, Stage III, the erosion toward the head, Stage IV, the expansion and incision of the breach, and Stage V, the re-equilibration of the river channel through the breach. It is shown that once triggered the entire breach process goes continually without stop, which highlights the significant impact of the early stages on the later deformation of the dam. Evidence shows that the initial breach of the dam is most likely to take place in the downstream slope of the dam, near the upper edge of the seepage face. The experimental results show a “headcut” mechanism of the breach initiation.
TL;DR: In this article, the influence of human activity on the sea water content, the sediment content and the regional transport situation in the Yangtze River Estuary was analyzed, showing that the sediment discharge rate and the suspended sediment concentration (SSC) in the estuary area of the river showed decreasing trends.
Abstract: With the Yangtze River Estuary as an example, this paper analyzes the influence of human activity on the sea water content, the sediment content and the regional transport situation. In both flood seasons and dry seasons, as well as in the whole year, the sediment discharge rate and the suspended sediment concentration (SSC) in the estuary area of the Yangtze River show decreasing trends. In the estuary area, the amount of sediment transported into the South and North Branches and the offshore area is also in a decreasing trend over the years. The SSCs at the sections at the entrances of the South Branch, the South Channel, the North Channel and the South Passage in the Yangtze River Estuary show decreasing trends during 1959-2011. The remote-sensing data reveal that for the same runoff and tidal current combination, the SSC in the surface water is decreased, caused by the dramatic decrease in the sediment discharge and the sediment content from the watershed. Although the SSC in the offshore area does not exhibit an apparent decreasing trend, the SSC in the nearshore area drops by 21.42% during the period of 2003-2011 as compared with that during the period of 1985-2002 before the impounding of the Three Gorges Reservoir. The sediment re-suspension in the estuary slows down the reduction of the SSC. The period of 2003-2011 is dry years for the Yangtze River, when the flow is relatively low. The peak value of the SSC in the coast area shifts inwards for about 1/6°degree of longitude. Due to the deepwater channel improvement project in the North Passage at the Yangtze River Estuary in 1998, the SSC in the waterway area is decreased. With the decrease of the divided flow ratio and the sediment splitting ratio in the entrance and the exit of the North Passage, the SSC in the upper and lower reaches of the North Passage during the period of 2008-2011 is decreased by about 14.25% as compared with that during the period of 2000-2007. Primarily due to the jetty at the south side, the SSC in the middle reach shows an increasing trend.
TL;DR: In this article, a sound pressure (P) and particle velocity (U) measurement probe was introduced for investigating this property on road surface samples in the laboratory, which can be applied in situ, thus no reverberant room or impedance tube is required in the test.
TL;DR: A novel and cost-effective fusion methodology to bridge GPS outages is proposed and applied in the Inertial Navigation System (INS)/GPS/ compass integrated positioning system and illustrates significant improvement in positioning accuracy during GPSOutages.
Abstract: Many intelligent transportation system applications require accurate, reliable, and continuous vehicle position information whether in open-sky environments or in Global Positioning System (GPS) denied environments. However, there remains a challenging task for land vehicles to achieve such positioning performance using low-cost sensors, especially microelectromechanical system (MEMS) sensors. In this paper, a novel and cost-effective fusion methodology to bridge GPS outages is proposed and applied in the Inertial Navigation System (INS)/GPS/ compass integrated positioning system. In the implementation of the proposed methodology, a key data preprocessing algorithm is first developed to eliminate the noise in inertial sensors in order to provide more accurate information for subsequent modeling. Then, a novel hybrid strategy incorporating the designed autoregressive model (AR model)-based forward estimator (ARFE) with Kalman filter (KF) is presented to predict the INS position errors during GPS outages. To verify the feasibility and effectiveness of the proposed methodology, real road tests with various scenarios were performed. The proposed methodology illustrates significant improvement in positioning accuracy during GPS outages.
TL;DR: In this paper, the feasibility of using potassium permanganate (KMnO4) as an oxidant to reduce 7 carcinogenic polycyclic aromatic hydrocarbons (PAHs) content in two coal tar pitches (CTPs), and to research the oxidation mechanism of KMnO 4.
Abstract: This study was conducted to assess the feasibility of using potassium permanganate (KMnO4) as an oxidant to reduce 7 carcinogenic polycyclic aromatic hydrocarbons (PAHs) content in two coal tar pitches (CTPs), and to research the oxidation mechanism of KMnO4. It had been observed reduction of major PAHs in CTP after KMnO4 oxidation. The best benzo[a]pyrene equivalency (BaPeq) reduction rate of 82% in n-hexane soluble in a high temperature CTP (HCTP) was achieved with KMnO4 concentration of 0.2 M treated for 5 h. Specifically, a higher phenanthrene reduction rate (90%) was obtained by using the Soxhlet extraction with n-hexane as solvent on the KMnO4 oxidized HCTP. The single PAH removal rate roughly increases with increasing rings number of PAH, following the order of phenanthrene
TL;DR: In this paper, the results of melting ice point (MIP) tests indicate that Mg-Al Cl − layered double hydroxide (LDH) is more effective in decreasing the MIP of water.
TL;DR: This research builds an assessment framework on the basis of an agent-based model, named ANEM, to explore nutrient mitigation potentials of five policy instruments, using pig production in Zhongjiang county, southwest China, as the empirical filling.
TL;DR: In this paper, the effect of emulsifier content on the properties of asphalt emulsion was analyzed through the analysis of the viscoelastic parameters, which indicated an enhanced resistance to deformation.
Abstract: Rheological measurement was employed to study the effect of emulsifier content on the properties of asphalt emulsion. Three kinds of emulsifiers are employed, and both temperature and frequency sweep were carried out in this study. Through the analysis of the viscoelastic parameters, the emulsifier content has an obvious influence in the properties of asphalt emulsions. As the content is higher, both the viscosity and modulus increase at a given temperature and/or frequency. The rut factor also increases with the emulsifier content, which indicates an enhanced resistance of emulsified asphalt mixtures to deformation. Rheological results can guide the selection of optimal emulsifier concentration for a given method of preparation. Results of softening point, penetration, ductility and storage stability also show good agreement with the rheological measurements. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41806.
24 Apr 2015
TL;DR: Roadside vegetation can perform many important functions, including the provision of habitat for rare plants and animals, a source of seeds for adjacent landscapes, a buffer to reduce the penetration of traffic noise and light, carbon sinks and enhanced aesthetics for road users as mentioned in this paper.
Abstract: The structure and composition of roadside vegetation vary from frequently mown grass to shrubs and trees and from artificial landscaping to natural plant communities. Roadside vegetation can perform many important functions, including the provision of habitat for rare plants and animals, a source of seeds for adjacent landscapes, a buffer to reduce the penetration of traffic noise and light, carbon sinks and enhanced aesthetics for road users. In certain situations, roadside vegetation can have negative effects, such as attracting wildlife and increasing rates of wildlife-vehicle collisions (WVC), creating movement corridors for weeds and invasive species, obscuring road signs and damaging road surfaces. 1 Roadsides can support rare and threatened species of plants and animals, and these should be managed for conservation. 2 Vegetation that reduces visibility or poses a traffic hazard should be managed to achieve a compromise between safety and biodiversity conservation. 3 Roadside habitats may act as ecological traps: It is preferable to recreate offset or compensation habitats away from roadsides. 4 The drainage of roads and roadsides must be designed to minimise impacts on adjacent vegetation and habitats. 5 Never plant invasive species (environmental weeds) along roads: Use plants native to the region for roadside soil stabilisation, shade, ornamental planting and control of noise and light pollution. 6 Perennial vegetation cover and ongoing management of roadside vegetation are required to control the continuous threat of weed invasion. 7 The reduction of fuel loads on roadsides should be compatible with biodiversity management objectives. The challenge for management is to comprehensively quantify and understand the role and values of roadside vegetation and manage roadsides to enhance their positive impacts and reduce their negative effects.
TL;DR: In this article, the results of this full-scale test along with a numerical study to evaluate the stress reductions achieved by the use of geogrid bridging platform installation are reported.
Abstract: Construction of new highway embankments in urban areas often requires building over existing underground utilities and lifelines. Embankments constructed over such utilities often induce substantial additional earth pressures causing overstressing and/or unacceptable deformations of the buried pipes, resulting in interruption of service for both the utility and highway. There are several techniques that can be used to mitigate this problem. Geogrid-reinforced bridge platforms are one of the newer techniques to deal with this problem. In order to gain a better understanding of the earth pressure reduction that may be achieved by geogrid bridging, the Ontario Ministry of Transportation (MTO) constructed an instrumented full-scale test embankment over a geogrid-reinforced bridged trench. In this paper, the results of this full-scale test along with a numerical study to evaluate the stress reductions achieved by the use of geogrid bridging platform installation are reported. In addition, results of a ...
TL;DR: In this paper, the moisture susceptibility of asphalt mixtures and binders containing Sasobit warm mix additive was investigated in comparison to that of hot mixture asphalt (HMA) through laboratory aging experiments.
Abstract: Moisture susceptibility is one of the key issues of warm mix asphalt (WMA). In this research, the moisture susceptibility of asphalt mixtures and binders containing Sasobit warm mix additive was investigated in comparison to that of hot mixture asphalt (HMA) through laboratory aging experiments. The WMA asphalt mixtures were aged in the laboratory at three aging temperatures and times. The moisture susceptibility of the asphalt mixtures was measured through the laboratory immersed Marshall test and freeze-thaw splitting test. The surface free energy (SFE) of asphalt binders extracted from WMA asphalt mixtures was determined by the sessile drop method. The results show that the aging time and temperature have a significant effect on the improvement in moisture susceptibility in terms of both the freeze-thaw splitting strength ratios and the residual Marshall stability of asphalt mixtures containing Sasobit warm mix additive. The SFE of asphalt binders extracted from Sasobit warm mix increased with the aging time and temperature. The moisture susceptibility of the asphalt mixtures and binders containing Sasobit warm mixes was similar to or even greater than that of HMA aging under certain conditions.
TL;DR: It is shown that certain factors do not have the same impact on driving behavior, in various conditions, and it will be possible to define certain critical groups of road users and the way in which they must be addressed in order to increase the seat belt wearing rate.
TL;DR: In this paper, the authors explored the factors of female taxi drivers' speeding offenses in Taiwan and found that the determinant factors associated with female taxi driver’s speeding offenses are significantly related to age, educational level and mileage driven.
Abstract: Females choosing taxi driving as a career is rare, therefore, investigating such samples is often difficult. Speeding is one of the most common driving violations, however, there has been no research looking into female taxi drivers’ speeding issue. This study explores the factors of female taxi drivers’ speeding offenses in Taiwan. Data is based on a national survey and includes 235 professional female taxi drivers. The results indicate that female taxi drivers work approximately 27.37 days per month, at a mean of 9.76 h per day. Of the female taxi drivers represented in this study, 22.8% reported at least one speeding offense over a one-year period. The results of a logistic regression model reveal that the determinant factors associated with female taxi drivers’ speeding offenses are significantly related to age, educational level and mileage driven. However, job experience, business operating style, and vehicle engine size are not associated with committing speeding offenses. Practical implications for traffic safety of female taxi drivers are also discussed.
TL;DR: In this article, a 180-day incubation experiment was conducted to investigate the effect of different organic materials on the chemical properties of coastal soil with high salinity and relatively low pH.
Abstract: A 180-day incubation experiment was conducted to investigate the effect of different organic materials on the chemical properties of coastal soil with high salinity and relatively low pH. Four organic materials (three kinds of plant residues: straw, composted straw, and fresh reed; and one kind of poultry manure: chicken manure) were applied at a ratio of 15 g·kg−1 to samples of costal saline soil from the Yellow River Delta of China. The results showed that the soil pH and exchangeable sodium percentage (ESP) decreased, whereas soil cation exchangeable capacity (CEC) and macronutrient concentrations increased, regardless of the type of organic material used. All treatments showed a remarkable increase in soil soluble organic carbon (SOC) during the 180-day incubation. The peak values of SOC in descending order were chicken manure, reed, composted straw, straw, and control soil. At the end of incubation, the highest level of SOC occurred in the straw-amended soil, followed by composted straw, reed, and chicken manureamended soils. Soil respiration rate and available nitrogen were significantly influenced by the type of material used. Although reed-amended soil had a relatively high SOC and respiration rate, the ESP was reduced the least. Considering the possible risk of heavy metals caused by chicken manure, it is proposed that straw and composted straw are the more efficient materials to use for reclaiming costal saline soil and improving the availability of macronutrients.
TL;DR: In this article, a Structural equation modeling was used to understand the complex variable relationships between online searching, e-shopping and shopping trip in Indonesia, and the results showed that online shopping can replace the shopping travel demand, while in-store shopping has no effect on the demand of online shopping.
Abstract: This paper provides more insights into the relationships between online searching, e-shopping and shopping trip in Indonesia. It becomes attractive since nearly a fifth of total population use internet for searching product information and online shopping. An online survey was used to collect the data. Out of 312 respondents participating, only 281 respondents were selected residing in thirteen provinces in Indonesia. A Structural equation modeling was used to understand the complex variable relationships. The result shows that online shopping can replace the shopping travel demand. However, in-store shopping has no effect on the demand of online shopping. Meanwhile, online searching is not only increasing the frequency of e-shopping, but also generating a more often shopping trips. This study also found that both e-shopping and in-store shopping are influenced by exogenous factors such as shoppers' demographic features, household socio-economy, shopping characteristic and shopping attitude.