Investigation on the Temperature Distribution of Asphalt Overlay on the Existing Cement Concrete Pavement in Hot-Humid Climate in Southern China

Temperature is known to be one of the most important factors affecting the design and performance of asphalt concrete pavement. The distresses of asphalt overlay are closely related to its temperature, particularly in Guangxi, a hot-humid-climate region in China. This research is to analyze the impact of meteorological factors on temperature at 2 cm depth in asphalt overlay by ReliefF algorithm and also obtain the temperature prediction model using MATLAB. Two test sites were installed to monitor the temperatures at different pavement depths from 2014 to 2016; meanwhile, the meteorological data (including air temperature, solar radiation, wind speed, and relative humidity) were collected from the two meteorological stations. It has been found that the temperature at 2 cm depth experiences greater temperature variation, and the maximum and minimum temperatures of asphalt overlay, respectively, occur at 2 cm depth and on the surface. Besides, the results of ReliefF algorithm have also shown that the temperature at 2 cm depth is affected significantly by solar radiation, air temperature, wind speed, and the relative humidity. Based on these analyses, the prediction model of maximum temperature at 2 cm depth is developed using statistical regression. Moreover, the data collected in 2017 are used to validate the accuracy of the model. Compared with the existing models, the developed model was confirmed to be more effective for temperature prediction in hot-humid region. In addition, the analysis of rutting depth and overlay deformation for the two test sections with different materials is done, and the results have shown that reasonable structure and materials of asphalt overlay are vital to promote the high-temperature antideforming capability of pavement.

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Efectos de las condiciones ambientales sobre el comportamiento ingestivo en bovinos de carne en un sistema intensivo en el Valle del Sinú

Ciencia y Tecnología Agropecuaria ◽

10.21930/rcta.vol13_num2_art:257 ◽

2013 ◽

Vol 13 (2) ◽

pp. 207 ◽

Cited By ~ 2

Author(s):

Emiro Suárez P. ◽

Sony Reza G. ◽

Eliecer Díaz A. ◽

Fredy García C. ◽

Iván Pastrana V. ◽

...

Keyword(s):

Wind Speed ◽

Relative Humidity ◽

Solar Radiation ◽

Beef Cattle ◽

Air Temperature ◽

Ingestive Behavior ◽

Average Weight ◽

Zebu Cattle ◽

Panicum Maximum ◽

Atmospheric Variables

Incrementos en la temperatura ambiental y la humedad relativa, unidas al efecto de la radiación solar, ocasionan pérdidas en el bienestar animal, afectando la conducta ingestiva y la productividad animal. Por ello el objetivo de este estudio fue analizar las relaciones entre las variables atmosféricas, como temperatura del aire, humedad relativa, velocidad del viento y radiación solar, con los tiempos de pastoreo y de rumia de bovinos cebú comercial. La investigación se llevó a cabo durante 96 días, entre julio-octubre de 2010, en el C.I. Turipaná de Corpoica (Cereté, Colombia). Bovinos machos enteros (27), con peso promedio 314 ± 29 kg, pastorearon en un área de 18 hectáreas, establecidas en Panicum maximum cv. Mombasa, Cynodonnlem fluensis y Brachiaria híbrido cv. Mulato II, sin disponibilidad de sombra. Se realizaron ocho evaluaciones durante 8 días dentro del periodo experimental de las variables atmosféricas e ingestivas y las anotaciones se hicieron en un lapso de 12 horas continuas (6:00 AM a 6:00 PM). Los resultados resaltan que al aumentar la temperatura del aire, humedad relativa y la radiación solar, disminuyó el tiempo de pastoreo y aumentó el tiempo de rumia, mientras que al aumentar la velocidad del viento se incrementó el tiempo de pastoreo y disminuyó el tiempo de rumia. Los resultados obtenidos indicaron que la temperatura del aire, humedad relativa, radiación solar y velocidad del viento, presentaron una influencia directa sobre el comportamiento ingestivo de los bovinos de carne manejados en sistemas intensivos (sin sombra) en el Valle del Sinú. Effects of environmental conditions on feeding behavior in beef cattle in an intensive system in the Sinú Valley Increases in temperature and relative humidity together with the solar radiation effect are detrimental to animal welfare, affecting their behavior when it comes to feeding and digestive behavior, which affects their productivity. Therefore, the goal of this research was to analyze the link between atmospheric variables, air temperature, relative humidity, wind speed and solar radiation to the time of grazing and rumination of commercial Zebu cattle. The research took place from July to October 2010, at the Turipaná Center, Corpoica (Cereté, Colombia). Male intact bovines (27), with an average weight of 314 ± 29 kg, grazed in an area of 18 hectares, established with Panicum maximum cv. Mombasa, Cynodonnlem fluensis and Brachiaria hybrid cv. Mulato II, without shade availability. Eight evaluations were conducted for 8 days in the experimental period for atmospheric variables and ingestion. Notes were taken in 12 hour time frames (6:00 AM a 6:00 PM). The outcome showed that as the air temperature, relative humidity and solar radiation increased, the grazing time decreased and rumination time lasted longer. However, when wind speed increased, grazing time increased as well and rumination took less time. The results showed that the air temperature, relative humidity, solar radiation and wind speed had a direct influence on the ingestive behavior of beef cattle managed in intensive systems (shadeless) in Valle del Sinú.

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Estimation of the Influence of Meteorological Factors on the Potential Evapotranspiration of Yanhe River Basin

10.22541/au.161123412.25069249/v1 ◽

2021 ◽

Author(s):

yu luo ◽

Peng Gao ◽

Xingmin Mu ◽

dexun Qiu

Keyword(s):

Wind Speed ◽

Relative Humidity ◽

Solar Radiation ◽

River Basin ◽

Air Temperature ◽

Meteorological Factors ◽

Sensitivity Coefficient ◽

Downward Trend ◽

Upward Trend ◽

Temporal And Spatial

Potential evapotranspiration (ET) is an important expenditure item in the hydrological cycle. Quantitative estimation of the influence of meteorological factors on ET can provide a scientific basis for the study of the impact mechanism of climate change on the hydrological cycle. In this paper, the Penman-Monteith method was used to calculate ET. The Mann-Kendall statistical test and the Inverse Distance Weighting method were used to analyze the temporal and spatial characteristics of the sensitivity coefficient of ET to meteorological factors and contribution rate of meteorological factors to ET. And the reasons for the change of ET were quantitatively explored in combination with the change trend of meteorological factors. The results showed that the average ET in the Yanhe River Basin from 1978 to 2017 was 935.92mm. Except for Ganquan Station, ET showed an upward trend. Generally, the sensitivity coefficient of air temperature (0.08), wind speed (0.19) and solar radiation (0.42) was positive and the sensitivity coefficient of relative humidity (-0.41) was negative. But there were significant temporal and spatial differences. The upward trend of air temperature and solar radiation contributed 1.09% and 0.55% to ET. Respectively, the downward trend of wind speed contributed -0.63% And the downward trend of relative humidity contributed to -0.85% of ET. Therefore, the decrease of relative humidity did not cause the increase of ET in Yanhe River basin. The dominant factor of the upward trend of ET was air temperature. But the dominant factors of ET had significant temporal and spatial differences. The downward trend of wind speed at Ganquan Station contributed -9.16% to ET, which indicated the dominant factor of “evaporation paradox” in Ganquan area was wind speed. Generally, the increase of ET was related to air temperature, wind speed and solar radiation. And the decrease of ET was related to relative humidity.

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Indoor Thermal Performance of Ventilated Dwellings Using Fly Screens in the Hot-Humid Climate of Chennai, India

Journal of Green Building ◽

10.3992/jgb.4.2.150 ◽

2009 ◽

Vol 4 (2) ◽

pp. 150-157 ◽

Cited By ~ 1

Author(s):

Vijayalaxmi J ◽

S.P Sekar

Keyword(s):

Solar Radiation ◽

Air Temperature ◽

Thermal Performance ◽

Indoor Air ◽

Tropical Climate ◽

Summer Period ◽

Humid Climate ◽

Floor Area ◽

Hot Humid Climate ◽

Heating Up

In a hot-humid tropical climate, indoor thermal performance can be enhanced by comfort ventilation. Indoor ventilation depends upon building opening size. But risks involved in providing openings include ingress of mosquitoes and insects which thrive in the tropical climate. A practical and prevalent option to prevent insects in ventilated dwellings of the tropical, hot-humid city of Chennai, India is through the use of fly screens. Fly screens, when used over openings, prevent a certain quantum of solar radiation and wind from entering inside the rooms. Reduced direct solar radiation prevents the indoors from heating up, while reduced wind movement prevents the cross ventilation. Therefore, it is important to know the indoor thermal performance of ventilated rooms in the presence of fly screens with changing opening sizes. The criterion to evaluate indoor thermal performance in this paper is indoor air temperature. The aim of this research is to investigate the influence of fly screens on openings with varying sizes, in a naturally ventilated dwelling in the hot-humid climate of Chennai, India, during the summer period. The results of the study show that fly screens raise the indoor air temperature when openings are in the range of 100% to 35% of the room floor area. There is no significant change in the indoor air temperature when the opening sizes are less than 30% of the room floor area.

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Influence of Meteorological Factors on the Potential Evapotranspiration in Yanhe River Basin, China

10.22541/au.161606525.58625543/v1 ◽

2021 ◽

Author(s):

yu luo ◽

Peng Gao ◽

Xingmin Mu

Keyword(s):

Wind Speed ◽

Relative Humidity ◽

Solar Radiation ◽

River Basin ◽

Air Temperature ◽

Hydrological Cycle ◽

Meteorological Factors ◽

Potential Evapotranspiration ◽

Sensitivity Coefficients ◽

The Impact

Potential evapotranspiration (ET) is an essential component of the hydrological cycle, and quantitative estimation of the influence of meteorological factors on ET can provide a scientific basis for studying the impact mechanisms of climate change. In the present research, the Penman-Monteith method was used to calculate ET. The Mann-Kendall statistical test with the inverse distance weighting were used to analyze the spatiotemporal characteristics of the sensitivity coefficients and contribution rates of meteorological factors to ET to identify the mechanisms underlying changing ET rates. The results showed that the average ET for the Yanhe River Basin, China from 1978–2017 was 935.92 mm. Save for a single location (Ganquan), ET increased over the study period. Generally, the sensitivity coefficients of air temperature (0.08), wind speed at 2 m (0.19), and solar radiation (0.42) were positive, while that of relative humidity was negative (-0.41), although significant spatiotemporal differences were observed. Increasing air temperature and solar radiation contributed 1.09% and 0.55% of the observed rising ET rates, respectively; whereas decreasing wind speed contributed -0.63%, and relative humidity accounted for -0.85%. Therefore, it was concluded that the decrease of relative humidity did not cause the observed ET increase in the basin. The predominant factor driving increasing ET was rising air temperatures, but this too varied significantly by location and time (intra- and interannually). Decreasing wind speed at Ganquan Station decreased ET by -9.16%, and was the primary factor underlying the observed, local “evaporation paradox.” Generally, increases in ET were driven by air temperature, wind speed and solar radiation, whereas decreases were derived from relative humidity.

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Influence of Courtyard Ventilation on Thermal Performance of Office Building in Hot-Humid Climate: A Case Study

E3S Web of Conferences ◽

10.1051/e3sconf/20183402053 ◽

2018 ◽

Vol 34 ◽

pp. 02053

Author(s):

Esra’a Sh. Abbaas ◽

Ala’eddin A. Saif ◽

MAC Munaaim ◽

Md. Azree Othuman Mydin

Keyword(s):

Relative Humidity ◽

Air Temperature ◽

Thermal Performance ◽

Natural Ventilation ◽

Office Building ◽

Humid Climate ◽

Airborne Pollutants ◽

Indoor Sources ◽

Hot Humid Climate

The influence of courtyard on the thermal performance of Development Department office building in University Malaysia Perlis (UniMAP, Pauh Putra campus) is investigated through simulation study for the effect of ventilation on indoor air temperature and relative humidity of the building. The study is carried out using EnergyPlus simulator interface within OpenStudio and SketchUp plug in software to measure both of air temperature and relative humidity hourly on 21 April 2017 as a design day. The results show that the ventilation through the windows facing the courtyard has sufficient effect on reducing the air temperature compared to the ventilation through external windows since natural ventilation is highly effective on driving the indoor warm air out to courtyard. In addition, the relative humidity is reduced due to ventilation since the courtyard has high ability to remove or dilute indoor airborne pollutants coming from indoor sources. This indicates that the presence of courtyard is highly influential on thermal performance of the building.

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Influence of Meteorological Factors on the Potential Evapotranspiration in Yanhe River Basin, China

Water ◽

10.3390/w13091222 ◽

2021 ◽

Vol 13 (9) ◽

pp. 1222

Author(s):

Yu Luo ◽

Peng Gao ◽

Xingmin Mu

Keyword(s):

Wind Speed ◽

Relative Humidity ◽

Solar Radiation ◽

River Basin ◽

Air Temperature ◽

Hydrological Cycle ◽

Meteorological Factors ◽

Potential Evapotranspiration ◽

Sensitivity Coefficients ◽

The Impact

Potential evapotranspiration (ET0) is an essential component of the hydrological cycle, and quantitative estimation of the influence of meteorological factors on ET0 can provide a scientific basis for studying the impact mechanisms of climate change. In the present research, the Penman–Monteith method was used to calculate ET0. The Mann–Kendall statistical test with the inverse distance weighting were used to analyze the spatiotemporal characteristics of the sensitivity coefficients and contribution rates of meteorological factors to ET0 to identify the mechanisms underlying changing ET0 rates. The results showed that the average ET0 for the Yanhe River Basin, China from 1978–2017 was 935.92 mm. Save for a single location (Ganquan), ET0 increased over the study period. Generally, the sensitivity coefficients of air temperature (0.08), wind speed at 2 m (0.19), and solar radiation (0.42) were positive, while that of relative humidity was negative (−0.41), although significant spatiotemporal differences were observed. Increasing air temperature and solar radiation contributed 1.09% and 0.55% of the observed rising ET0 rates, respectively; whereas decreasing wind speed contributed −0.63%, and relative humidity accounted for −0.85%. Therefore, it was concluded that the decrease of relative humidity did not cause the observed ET0 increase in the basin. The predominant factor driving increasing ET0 was rising air temperatures, but this too varied significantly by location and time (intra- and interannually). Decreasing wind speed at Ganquan Station decreased ET0 by −9.16%, and was the primary factor underlying the observed, local “evaporation paradox”. Generally, increase in ET0 was driven by air temperature, wind speed and solar radiation, whereas decrease was derived from relative humidity.

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Seasonal Variation and Characterization of the Micrometeorology in Linpan Settlements in the Chengdu Plain, China: Microclimatic Effects of Linpan Size and Tree Distribution

Advances in Meteorology ◽

10.1155/2019/3272581 ◽

2019 ◽

Vol 2019 ◽

pp. 1-13 ◽

Cited By ~ 1

Author(s):

Hua Zong ◽

De-hua Pu ◽

Mei-lin Liu

Keyword(s):

Wind Speed ◽

Relative Humidity ◽

Solar Radiation ◽

Air Temperature ◽

Radiation Flux ◽

Negative Relationship ◽

Distribution Patterns ◽

Tree Distribution ◽

Chengdu Plain ◽

Solar Radiation Flux

Linpan settlements (abbreviated as Linpan) are the most important traditional type of rural settlement in the Chengdu Plain, and they are an important part of the agroforestry ecological system in southwest China. In this study, we measured the micrometeorological parameters (air temperature, solar radiation, relative humidity, and wind speed) in 12 Linpans for two years to determine the seasonal micrometeorology variations; then, we explored the impacts of Linpan size and tree distribution on the Linpan micrometeorology. The results show that the Linpans undergo seasonal cooling (from 0.6 to 1.3°C), humidification (from 0.9% to 4.1%), reduction in solar radiation flux (from 92.1 to 496.0 W/m2), and changes in wind speed (by 0.4 to 0.5 m/s) compared to the surrounding environment. Both solar radiation flux and wind speed showed the following decreasing trend with respect to sampling positions in the Linpan: outside > edge > center. The Linpan size did not affect the solar radiation flux or wind speed over the four seasons. The main factor affecting solar radiation flux and wind speed was the horizontal tree distribution not the Linpan size. However, the Linpan size was significantly correlated with the air temperature in summer and winter. Large Linpans (>5 × 103 m2) showed better ability to control the temperature to within a comfortable range in extremely hot and cold seasons. The Linpan size also showed a negative relationship with the relative humidity, but only in winter. Among the tree distribution patterns, a scattered distribution was optimal to achieve a comfortable micrometeorology over the course of the year. In addition, we suggest some ways to adapt the Linpan micrometeorology, which could be used to protect traditional Linpans, as well as for ecological restoration.

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Prediction of Temperature Distribution for Previous Cement Concrete Pavement with Asphalt Overlay

Applied Sciences ◽

10.3390/app10113697 ◽

2020 ◽

Vol 10 (11) ◽

pp. 3697

Author(s):

Lijuan Zhang ◽

Jianwu Huang ◽

Peilong Li

Keyword(s):

Temperature Distribution ◽

Solar Radiation ◽

Air Temperature ◽

Climatic Factors ◽

Concrete Pavement ◽

Inverse Laplace Transform ◽

Surface Boundary ◽

Cement Concrete ◽

Asphalt Overlay ◽

Cement Concrete Pavement

In this study, the temperature distribution of a pavement was predicted by developing an analytic algorithm. The Laplace and inverse Laplace transform techniques and Gaussian quadratic formula were applied to a pavement system of an asphalt overlay placed over an existing concrete pavement. The temperature distribution of the previous cement concrete pavement with an asphalt overlay can be estimated with the proposed analytical method regardless of the depth and time. To conduct the method, the layer thicknesses, material thermal properties and climatic factors (including air temperature, wind velocity and solar radiation) were firstly input. Then, a discrete least-squares approximation of the interpolatory trigonometric polynomials was used to fit some specific measured climatic factors considered in the surface boundary condition, i.e., the measured solar radiation intensity and air temperature. The pavement surface convection coefficient can be approximately calculated by the wind speed. The temperature solutions are validated with the measured pavement temperature data of two different periods of a whole year (summer and winter). The obtained results demonstrate the feasibility of the developed analytical approach to predict the temperature distribution of the existing cement concrete pavement with an asphalt overlay in different weather conditions with acceptable accuracy.

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Relationship of air temperature, relative humidity, precipitation, photoperiod, wind speed and solar radiation with serum insulin-like growth factor I (IGF-I) concentration in angus beef cattle

Domestic Animal Endocrinology ◽

10.1016/0739-7240(94)90019-1 ◽

1994 ◽

Vol 11 (3) ◽

pp. 281-290 ◽

Cited By ~ 8

Author(s):

T.A. Sarko ◽

M.D. Bishop ◽

M.E. Davis

Keyword(s):

Growth Factor ◽

Wind Speed ◽

Relative Humidity ◽

Solar Radiation ◽

Beef Cattle ◽

Air Temperature ◽

Serum Insulin ◽

Factor I ◽

Igf I ◽

Relationship Of

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Impact of Micro-climatic variations on Forest Ecosystem in Mid Hills of Himachal Pradesh

Current World Environment ◽

10.12944/cwe.12.1.12 ◽

2017 ◽

Vol 12 (1) ◽

pp. 97-106 ◽

Cited By ~ 1

Author(s):

Purnima Mehta ◽

P. K Baweja ◽

R. K. Aggarwal

Keyword(s):

Wind Speed ◽

Relative Humidity ◽

Solar Radiation ◽

Soil Temperature ◽

Air Temperature ◽

Forest Ecosystem ◽

Forest Canopy ◽

Oak Forest ◽

Bare Area ◽

Climatic Variations

A study was carried out on “Impact of micro-climatic variations on forest ecosystem in mid hills of Himachal Pradesh” during winter and summer seasons of 2015-16. Comparisons of below forest canopy and open sites were carried out for abiotic and biotic factors under five forest ecosystems (chir pine forest, mixed forest, ban oak forest, agriculture field and bare area) and analysed the forest influence on local winter and summer climate according to forest type, soil type, slope orientation, tree height and diameter at breast height by using RBD design. Seasonal and diurnal variations in microclimatic variables viz., air temperature, soil temperature, relative humidity, wind speed and wind direction were measured with Portable weather station (Delta T) at afternoon 2:00-4:00 PM fortnightly in each forest ecosystem and bare area during winter and summer season. Solar radiation and albedo were measured with Pyranometer (Kipp and Zonen) at 1.35 m height. A significant decrease was attained in below forest canopy and bare area data for ambient temperature (2.5-5.0 oC), soil temperature (1.5-3.6 oC) solar radiation (13.2-47.4 Wm-2), albedo (0.15-0.21) and increased relative humidity (7-18%), soil moisture (8.0-15.2%). Among different forest ecosystem, the diurnal trends in microclimatic parameters showed large variations. The ambient air temperature ranged from 02.2-16.3 oC and 14.2- 30.7 oC where as soil temperature ranged from 07.4- 16.5 oC and 15.4-32.7 oC, however relative humidity ranged from 37- 88 per cent and 14-60 per cent among different forest ecosystem during winter and summer seasons, respectively. Mico-climatic variables under Ban-Oak forest revealed significant lowest air temperature, highest relative humidity and less wind speed.

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