Modelling pavement temperature for winter maintenance operations

2004 ◽  
Vol 31 (2) ◽  
pp. 369-378 ◽  
Author(s):  
Aly Sherif ◽  
Yasser Hassan
Keyword(s):  
Surface Temperature ◽  
Air Temperature ◽  
Negative Impact ◽  
Weather Conditions ◽  
Statistical Modelling ◽  
Dew Point ◽  
Road Maintenance ◽  
Winter Maintenance ◽  
Pavement Surface ◽  
Pavement Temperature

Road and highway maintenance is vital for the safety of citizens and for enabling emergency and security services to perform their essential functions. Accumulation of snow and (or) ice on the pavement surface during the wintertime substantially increases the risk of road crashes and can have negative impact on the economy of the region. Recently, road maintenance engineers have used pavement surface temperature as a guide to the application of deicers. Stations for road weather information systems (RWIS) have been installed across Europe and North America to collect data that can be used to predict weather conditions such as air temperature. Modelling pavement surface temperature as a function of such weather conditions (air temperature, dew point, relative humidity, and wind speed) can provide an additional component that is essential for winter maintenance operations. This paper uses data collected by RWIS stations at the City of Ottawa to device a procedure that maximizes the use of a data batch containing complete, partially complete, and unusable data and to study the relationship between the pavement surface temperature and weather variables. Statistical models were developed, where stepwise regression was first applied to eliminate those variables whose estimated coefficients are not statistically significant. The remaining variables were further examined according to their contribution to the criterion of best fit and their physical relationships to each other to eliminate multicollinearities. The models were further corrected for the autocorrelation in their error structures. The final version of the developed models may then be used as a part of the decision-making process for winter maintenance operations.Key words: winter maintenance, pavement temperature, statistical modelling, RWIS.

scholarly journals Moisture content of cereals at harvesting time by comparing microclimate values and standard weather data

1993 ◽  
Vol 41 (3) ◽  
pp. 167-178
Author(s):  
A.J. Atzema
Keyword(s):  
Moisture Content ◽  
Surface Temperature ◽  
Air Temperature ◽  
Weather Conditions ◽  
Dew Point ◽  
Weather Data ◽  
Daily Cycle ◽  
The Difference ◽  
High Equilibrium ◽  
Screen House

The moisture content of wheat and barley together with the weather elements were measured at 3 different experimental sites in the Netherlands in 1990-91. The difference in the dew point temperature in the screen[house] and in the field was small. However, the differences between air temperature in the screen and those at different heights in wheat and in barley stands were considerable. In daytime the surface temperature of barley was higher than that of wheat under the same weather conditions as a result of a higher absorbtion coefficient. Both for wheat and barley, the maximum difference between the calculated moisture content was 0.5%, using the air temperature at 1.5 m height from the nearest standard weather station and the surface temperature of the spikes. Barley had a greater daily cycle in the moisture content of the grains than wheat as a result of a high equilibrium moisture content during the night and a low one in daytime.

Measurement of indoor environmental parameters and analysis of the condensation phenomenon in urban utility tunnels

2022 ◽  
pp. 1420326X2110564
Author(s):  
Chuanmin Tai ◽  
Guansan Tian ◽  
Wenjun Lei
Keyword(s):  
Water Supply ◽  
Surface Temperature ◽  
Air Temperature ◽  
Natural Ventilation ◽  
Environmental Parameters ◽  
Dew Point ◽  
Control Mode ◽  
Safe Management ◽  
Environmental Test ◽  
Water Supply Pipeline

Condensation is a major issue in the safe operation of utility tunnels. To address the condensation problem, the indoor air temperature, relative humidity (RH) and surface temperature in an urban utility tunnel in Jining were continuously measured, and the condensation conditions were surveyed and analysed. The results indicated that under natural ventilation conditions, the air temperature in the comprehensive cabin varied from 23.4°C to 24.5°C, the RH fluctuated between 86.4% and 95.3%, and the corresponding air dew point temperature (DPT) remained in the range of 22.2°C–22.9°C. The surface temperature of the water supply pipeline ranged from 17.8°C to 18.5°C, which was far lower than the DPT in the tunnel, resulting in serious condensation. A water supply pipeline with an anti-condensation design was developed based on environmental test data. A 25-mm-thick rubber plastic sponge insulation layer was used to thermally insulate the water supply pipeline, preventing further dew condensation. Furthermore, mechanical ventilation had little effect on reducing the RH in the tunnel and may actually cause dew condensation; therefore, a ventilation control mode was proposed in this study. These results are expected to provide basic data for further research and reference for the safe management of utility tunnels.

scholarly journals Sea surface temperature variations in the south-eastern BalticSea in 1960–2015

Baltica ◽  
2018 ◽  
Vol 30 (2) ◽  
pp. 75-85 ◽  
Author(s):  
Viktorija Rukšėnienė ◽  
Inga Dailidienė ◽  
Loreta Kelpšaitė-Rimkienė ◽  
Tarmo Soomere
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Air Temperature ◽  
Weather Conditions ◽  
Sea Surface ◽  
South Eastern ◽  
Air Temperatures ◽  
Joint Application ◽  
Open Sea ◽  
And Cluster Analysis

This study focuses on time scales and spatial variations of interrelations between average weather conditions and sea surface temperature (SST), and long-term changes in the SST in south-eastern Baltic Sea. The analysis relies on SST samples measured in situ four times a year in up to 17 open sea monitoring stations in Lithuanian waters in 1960–2015. A joint application of non-metric multi-dimensional scaling and cluster analysis reveals four distinct SST regimes and associated sub-regions in the study area. The increase in SST has occurred during both winter and summer seasons in 1960–2015 whereas the switch from relatively warm summer to colder autumn temperatures has been shifted by 4–6 weeks over this time in all sub-regions. The annual average air temperature and SST have increased by 0.03°C yr–1 and 0.02°C yr–1, respectively, from 1960 till 2015. These data are compared with air temperatures measured in coastal meteorological stations and averaged over time intervals from 1 to 9 weeks. Statistically significant positive correlation exists between the SST and the average air temperature. This correlation is strongest for the averaging interval of 35 days.

IV.—A Note on the Secular Changes of Rock Temperature on the Calton Hill

1932 ◽  
Vol 51 ◽  
pp. 19-24
Author(s):  
F. J. W. Whipple
Keyword(s):  
Surface Temperature ◽  
Air Temperature ◽  
Weather Conditions ◽  
Temperature Variations ◽  
Secular Changes ◽  
Rock Temperature ◽  
The Mean

1. The observations of rock temperature on the Calton Hill have recently been analysed by Mr R. W. Wrigley, with a view to the discovery of changes going on gradually and independent of weather conditions. Mr Wrigley took groups of years, such that the mean air temperature was the same for each group, and found the mean rock temperature for like periods. He trusted that in this way he would be able “to get rid of the surface temperature variations.” The result of the calculations was that for different periods in which the mean air temperature was the same the temperature of the rock might vary by half a degree Fahrenheit. The rock temperature had a maximum about 1856, fell until 1892, and rose after that date.

Harvesting Thermoelectric Energy from Asphalt Pavements

2017 ◽  
Vol 2628 (1) ◽  
pp. 12-22 ◽  
Author(s):  
Utpal Datta ◽  
Samer Dessouky ◽  
A. T. Papagiannakis
Keyword(s):  
Surface Temperature ◽  
Field Experiments ◽  
Asphalt Pavement ◽  
Electrical Power ◽  
Weather Conditions ◽  
Research Field ◽  
South Texas ◽  
Element Analysis ◽  
Pavement Surface ◽  
Thermoelectric Energy

The goal of this study was to develop a prototype for harvesting thermoelectric energy from asphalt pavement roadways. This emerging research field encompasses technologies that capture the existing thermal energy in pavements to generate electricity without depleting natural resources. In lower latitudes, such as south Texas, the asphalt pavement surface temperature in the summer can reach 55°C because of solar radiation. Soil temperatures below the pavement, however, are roughly constant (i.e., 27°C to 33°C) at relatively shallow depths (150 mm). This thermal gradient between the surface temperature and the pavement substrata can be used to generate electrical power through thermoelectric generators (TEGs). The proposed prototype collects heat energy from the pavement surface and transfers the energy to a TEG embedded in the subgrade at the edge of the pavement shoulder. Evaluation of this prototype was carried out through finite element analysis, laboratory testing, and field experiments. The results suggest that the 64- × 64-mm TEG prototype can generate an average of 10 mW of electric power continuously over a period of 8 h in the weather conditions in south Texas. Scaling up this prototype by using multiple TEG units could generate sufficient electricity to sustainably power low-watt LED lights and roadway and traffic sensors in off-grid, remote areas.

scholarly journals Evaporative Cooling Integrated with Solid Desiccant Systems: A Review

Energies ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5982
Author(s):  
Lanbo Lai ◽  
Xiaolin Wang ◽  
Gholamreza Kefayati ◽  
Eric Hu
Keyword(s):  
Air Temperature ◽  
Cooling System ◽  
Evaporative Cooling ◽  
Operating Cost ◽  
Weather Conditions ◽  
Dew Point ◽  
Air Conditioning System ◽  
Direct Evaporative Cooling ◽  
Dry Climates ◽  
Desiccant Material

Evaporative cooling technology (ECT) has been deemed as an alternative to the conventional vapor-compression air conditioning system for dry climates in recent years due to its simple structure and low operating cost. Generally speaking, the ECT includes two types of different technologies, direct evaporative cooling (DEC) and indirect evaporative cooling (IEC). Both technologies can theoretically reduce the air temperature to the wet-bulb temperature of outdoor air. The major difference between these two technologies is that DEC will introduce extra moisture to the supply air while IEC will not. The enhanced IEC, Maisotsenko-cycle (M-cyle) IEC, can even bring down the air temperature to the dew point temperature. The ECT integrated with solid desiccant systems, i.e., solid desiccant-assisted evaporative cooling technologies (SDECT), could make the technology applicable to a wider range of weather conditions, e.g., weather with high humidity. In this paper, the recent development of various evaporative cooling technologies (ECT), solid desiccant material and the integration of these two technologies, the SDECT, were thoroughly reviewed with respect to their configuration, optimization and desiccant unit improvement. Furthermore, modeling techniques for simulating SDECT with their pros and cons were also reviewed. Potential opportunities and research recommendations were indicated, which include improving the structure and material of M-cycle IEC, developing novel desiccant material and optimizing configuration, water consumption rate and operation strategy of SDECT system. This review paper indicated that the SDECT system could be a potential replacement for the conventional vapor-compressed cooling system and could be applied in hot and humid environments with proper arrangements.

COMPARISON ON COLORED COATING FOR ASPHALT AND CONCRETE PAVEMENT BASED ON THERMAL PERFORMANCE AND COOLING EFFECT

2016 ◽  
Vol 78 (5) ◽  
Author(s):  
Julia Md. Tukiran ◽  
Jamel Ariffin ◽  
Abdul Naser Abdul Ghani
Keyword(s):  
Surface Temperature ◽  
Air Temperature ◽  
Thermal Performance ◽  
Ground Surface ◽  
Concrete Pavement ◽  
Concrete Sample ◽  
Pavement Surface ◽  
Solar Reflectance ◽  
Parking Lot ◽  
Colored Coating

In tropical climate, pavement surface temperature could reach up higher than the air temperature due to solar-energy absorption by pavement during the daytime. Colored ground surface such as in pedestrian walkway, parking lot, and bicycle track may be able to reduce the heat absorbed by the pavements. This paper reports the thermal performance of five different colors of coating applied at asphalt and concrete pavement surface. In order to investigate the thermal performance and solar reflectance of the colored coating pavement, infrared thermometer and solar power meter as well as thermal imager procedure were used. From the statistical analysis, it was found that all the colored coating on asphalt and concrete sample demonstrate lower surface temperature compared to conventional or uncoated asphalt and concrete. The highest surface temperature reduction and solar reflectance recorded was for the white coated asphalt sample was 17°C and 0.61, while for the white coated concrete sample was 10°C and 0.78. ENVI-met simulation is used for evaluating the thermal impact of applying the samples in site study. This study can assist in choosing more appropriate colored coatings for ground surface of the urban environment (pedestrian walkway, parking lot, plaza, etc.), and thus contribute to the reduction of the air temperature due to the heat-transfer phenomena as well as improve outdoor thermal comfort and cityscape appearance.

Effects of Ambient Air Relative Humidity and Surface Temperature on Water Droplet Spreading Dynamics

2018 ◽  
Author(s):  
M. Jadidi ◽  
M. A. Farzad ◽  
J. Y. Trepanier ◽  
A. Dolatabadi
Keyword(s):  
Contact Angle ◽  
Relative Humidity ◽  
Surface Temperature ◽  
Air Temperature ◽  
Water Droplet ◽  
Superhydrophobic Surface ◽  
High Speed ◽  
Ambient Air ◽  
Dew Point ◽  
Droplet Spreading

Water droplet impact on horizontal glass, aluminum, and superhydrophobic surfaces is experimentally investigated using high speed imaging. Experiments are performed at three different relative humidities (i.e. 10, 20 and 30%) and three surface temperatures (i.e. 20, 2 and −2°C) to ascertain their effects on droplet spreading and recoil behaviors. In this study, the droplet Weber number, Reynolds number, and the ambient air temperature are fixed at 16.2, 1687, and 23°C, respectively. The high-speed images of impact, spreading and recoil of the droplets as well as the temporal variations of droplet spreads are prepared. Results show that the ratio of surface temperature to dew point temperature (which depends on the air temperature and relative humidity) has a significant influence on droplet spreading, recoil, and contact angle. When this ratio is less than one, condensation and frost formation become important. Decreasing the mentioned ratio (it can be done by decreasing the surface temperature or increasing the relative humidity) causes the droplet spreading factor for hydrophilic surfaces to increase significantly. For superhydrophobic surface, decreasing this ratio (within the mentioned range) does not influence the maximum spreading. However, the recoiling phase is slowed down and the droplet detachment time form the superhydrophobic surface is increased noticeably. In addition, the equilibrium contact angle decreases as the mentioned ratio decreases.

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