Outdoor thermal environments and related planning factors for subtropical urban parks

2019 ◽  
pp. 1420326X1989146
Author(s):  
Jian Zhang ◽  
Zhonghua Gou ◽  
Yi Lu
Keyword(s):  
Thermal Environment ◽  
Urban Parks ◽  
Social Activities ◽  
Climate Data ◽  
Physiological Equivalent Temperature ◽  
Park Planning ◽  
Thermal Environments ◽  
Outdoor Environments ◽  
Tree Coverage ◽  
Thermal Indicators

Tropical or subtropical climates result in considerable heat stress in outdoor environments, which handicaps social activities in public spaces such as urban parks. This study aims to find out the effects of park planning factors on thermal environments. The research measured 18 urban parks around the city of Gold Coast in Australia from January to March 2018 which is the summer time of the Southern Hemisphere. Climate data were collected for each park, based on which park cooling intensity, mean radiant temperature and physiological equivalent temperature were calculated as thermal environment indicators. Meanwhile, park planning factors such as park tree coverage, park size and distance to major water bodies (the sea) were selected for multiple linear regressions with the thermal indicators. Our findings have confirmed that the park planning factors had significant effects on the thermal indicators. The effect of park tree coverage was most significant. This study provides important evidence and guidance for urban planning to create better outdoor thermal environments in parks to facilitate social activities.

scholarly journals Effects of Roadside Trees and Road Orientation on Thermal Environment in a Tropical City

2020 ◽  
Vol 12 (3) ◽  
pp. 1053 ◽  
Author(s):  
Sheikh Ahmad Zaki ◽  
Hai Jian Toh ◽  
Fitri Yakub ◽  
Ahmad Shakir Mohd Saudi ◽  
Jorge Alfredo Ardila-Rey ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Air Temperature ◽  
Thermal Environment ◽  
Absolute Humidity ◽  
Field Measurements ◽  
View Factor ◽  
Physiological Equivalent Temperature ◽  
Thermal Environments ◽  
Outdoor Thermal Environment ◽  
Tropical Cities

Emerging tropical cities are experiencing rapid population growth and development, which can greatly affect the thermal environments. The effects of roadside trees and road orientation on the outdoor thermal environment were investigated on four different roads in Kuala Lumpur, Malaysia. Field measurements were conducted to assess outdoor thermal environments, where the selection of sites was based on different roadside tree morphological features and road orientations. Outdoor air temperature (Ta), relative humidity (RH), globe temperature (Tg), wind speed (WS), and wind direction (WD) were measured. Absolute humidity (AH) was estimated based on relative humidity and air temperature. Planting dense canopy trees with an average sky view factor (SVF) of 0.07 reduced the mean radiant temperature (Tmrt) by 35% and the physiological equivalent temperature (PET) by 25%. East–West (E–W) and Northwest–Southeast (NW–SE) oriented roads had high PET values of 41 °C and 43 °C, respectively. North–South (N–S) and Northeast–Southwest (NE–SW) orientated roads had lower PET values (37 °C), providing improved outdoor microclimate. Roadside trees provided greater cooling potential in E–W and NW–SE oriented roads. The findings are useful for urban road design in tropical cities in order to improve the outdoor thermal environment and pedestrian comfort.

scholarly journals Climate-Responsive Green-Space Design Inspired by Traditional Gardens: Microclimate and Human Thermal Comfort of Japanese Gardens

2021 ◽  
Vol 13 (5) ◽  
pp. 2736
Author(s):  
Lihua Cui ◽  
Christoph D. D. Rupprecht ◽  
Shozo Shibata
Keyword(s):  
Thermal Stress ◽  
Thermal Comfort ◽  
Thermal Environment ◽  
Meteorological Data ◽  
Green Spaces ◽  
Physiological Equivalent Temperature ◽  
Urban Green Spaces ◽  
Thermal Environments ◽  
Human Thermal Comfort ◽  
Japanese Gardens

Urban green spaces can provide relaxation, exercise, social interaction, and many other benefits for their communities, towns, and cities. However, green spaces in hot and humid regions risk being underutilized by residents unless thermal environments are designed to be sufficiently comfortable. Understanding what conditions are needed for comfortable outdoor spaces, particularly how people feel in regard to their thermal environment, is vital in designing spaces for public use. Traditional gardens are excellent examples of successful microclimate design from which we can learn, as they are developed over the generations through observation and modification. This study analyzed how Japanese gardens affect people’s thermal stress on extremely hot summer days. Meteorological data was collected in three Japanese gardens, and human thermal comfort was evaluated through physiological equivalent temperature (PET). Statistical analysis examined the relationship between spatial configurations of the gardens and thermal comfort. Our study revealed that Japanese gardens can efficiently ameliorate thermal stress. Spatial analysis showed that garden elements affect thermal comfort variously depending on time of the day and spatial distribution.

Thermal status of sheep at pasture in western New South Wales

1971 ◽  
Vol 22 (5) ◽  
pp. 797 ◽  
Author(s):  
GD Brown
Keyword(s):  
Heat Stress ◽  
Thermal Environment ◽  
New South ◽  
New South Wales ◽  
Skin Surface ◽  
High Heat ◽  
South Wales ◽  
Temperature Telemetry ◽  
Thermal Status ◽  
Outdoor Environments

The thermal status of three unrestrained rams at pasture was studied for a period of 5 days during March in central western New South Wales. A temperature telemetry system was used to measure rectal temperatures, skin surface and subcutaneous temperatures on the mid back, and subcutaneous temperatures of the scrotum of each ram. Rectal temperatures of 40�C and above were recorded for all rams on each day, the highest recorded being 41 9 4 and 41.6�. Rectal temperatures in excess of 40� were also recorded for extended periods between 6.00 p.m. and midnight. Although respiratory frequencies increased with the increase in environmental heat load during the day, no obvious signs of extreme heat stress were noted at these elevated rectal temperatures, whereas sheep exposed to high heat loads in indoor experiments consistently exhibit heat stress at similar rectal temperatures. Rectal temperatures were generally higher and more variable than those reported by other workers for penned sheep in either indoor or outdoor environments. Subcutaneous scrota1 temperatures were usually lower than those which might be expected to induce sterility. Variations in the temperatures measured have been related to the thermal environment and patterns of behaviour of the sheep.

EFFECT OF THE THERMAL ENVIRONMENT ON COLD RESISTANCE AND GROWTH OF SMALL INFANTS AFTER THE FIRST WEEK OF LIFE

PEDIATRICS ◽  
1968 ◽  
Vol 41 (6) ◽  
pp. 1033-1046 ◽  
Author(s):  
Leonard Glass ◽  
William A. Silverman ◽  
John C. Sinclair
Keyword(s):  
Cold Resistance ◽  
Thermal State ◽  
Thermal Environment ◽  
Test Environment ◽  
Deep Body Temperature ◽  
Abdominal Skin ◽  
Thermal Environments ◽  
Rate Of Increase ◽  
Before And After ◽  
Deep Body

Twelve matched pairs of small (1,001-2,000 gm birth weight) asymptomatic neonates, age 1 week, were placed in either of two frequently recommended thermal environments ("standard": abdominal skin controlled at 35.0°C to approximate the thermal state commonly realized in nurseries for premature infants; "warm": abdominal skin controlled at 36.5°C to approximate thermoneutral condition). Both groups were fed 120 calories/kg/day. Before and after 2 weeks in the test environment, the infants were placed in a simulated room environment-28°C incubator wall—for 1 hour and the change in body temperatures was measured. Cold resistance–the ability to prevent a fall of deep body temperature in the 28°C environment– was significantly greater among infants who had spent 2 weeks in the slightly cooler environment. The rate of increase in body weight and length was significantly faster in the warmer condition.

Testing of the Mars Exploration Rovers to Survive the Extreme Thermal Environments

2007 ◽  
Vol 4 (4) ◽  
pp. 145-154
Author(s):  
Kin F. Man ◽  
Alan R. Hoffman
Keyword(s):  
Thermal Environment ◽  
Extreme Temperature ◽  
System Level ◽  
Thermal Testing ◽  
Mars Exploration ◽  
Thermal Environments ◽  
Diurnal Cycles ◽  
Operational Temperature ◽  
Science Laboratories

NASA's Mars Exploration Rover (MER) project involved delivering two mobile science laboratories (rovers) on the surface of Mars to remotely conduct geologic investigations, including characterization of a diversity of rocks and soils. The rovers were launched separately in 2003 and have been in operation on the surface of Mars since January 2004. The rovers underwent a comprehensive pre-launch environmental assurance program that included assembly/subsystem and system-level testing in the areas of dynamics, thermal, and electromagnetic (EMC), as well as venting/pressure, dust, radiation, and solid-particle (meteoroid, orbital debris) analyses. Due to the Martian diurnal cycles of extreme temperature swings, the susceptible hardware that were mounted outside of the thermal controlled zones also underwent thermal cycling qualification of their packaging designs and manufacturing processes. This paper summarizes the environmental assurance program for the MER project, with emphasis on the pre-launch thermal testing program for ensuring that the rover hardware would operate and survive the Mars surface temperature extremes. These test temperatures are compared with some of the Mars surface operational temperature measurements. Selected anomalies resulting from operating the rover hardware in the Mars extreme thermal environment are also presented.

scholarly journals Influence of Weather Factors on Thermal Comfort in Subtropical Urban Environments

2020 ◽  
Vol 12 (5) ◽  
pp. 2001 ◽  
Author(s):  
Chih-Hong Huang ◽  
Hsin-Hua Tsai ◽  
Hung-chen Chen
Keyword(s):  
Thermal Comfort ◽  
Urban Heat Island ◽  
Thermal Environment ◽  
Urban Environments ◽  
Heat Island ◽  
Weather Factors ◽  
Urban Forms ◽  
Thermal Environments ◽  
Island Effect ◽  
Urban Heat

Urbanization has influenced the distribution of heat in urban environments. The mutual influence between weather factors and urban forms created by dense buildings intensify human perception of the deteriorating thermal environment in subtropics. Past studies have used real-world measurements and theoretical simulations to understand the relationship between climate factors and the urban heat island effect. However, few studies have examined how weather factors and urban forms are connected to the thermal environment. To understand the influence of various weather factors on urban thermal environments in various urban forms, this study applied structural equation modeling to assumptions of linear relationships and used quantitative statistical analysis of weather data as well as structural conversion of this data to establish the structural relationships between variables. Our objective was to examine the relationships among urban forms, weather factors, and thermal comfort. Our results indicate that weather factors do indeed exert influence on thermal comfort in urban environments. In addition, the thermal comfort of urban thermal environments varies with location and building density. In hot and humid environments in the subtropics, humidity and wind speed have an even more profound impact on the thermal environment. Apparent temperature can be used to examine differences in thermal comfort and urban forms. This study also proved that an urban wind field can effectively mitigate the urban heat island effect. Ventilation driven by wind and thermal buoyancy can dissipate heat islands and take the heat away from urban areas.

Leading Indicators of Damage for Prognostication of Leadfree Electronics Subjected to Multiple Thermo-Mechanical Environments

2009 ◽  
Author(s):  
Pradeep Lall ◽  
Rahul Vaidya ◽  
Vikrant More ◽  
Jeff Suhling ◽  
Kai Goebel
Keyword(s):  
Residual Life ◽  
Thermal Environment ◽  
High Reliability ◽  
Damage State ◽  
Core System ◽  
Thermal Environments ◽  
Marquardt Algorithm ◽  
Tools And Techniques ◽  
Deployed Systems ◽  
Electronic Assemblies

Electronic assemblies deployed in harsh environments may be subjected to multiple thermal environments during the use-life of the equipment. Often the equipment may not have any macro-indicators of damage such as cracks or delamination. Quantification of thermal environments during use-life is often not feasible because of the data-capture and storage requirements, and the overhead on core-system functionality. There is need for tools and techniques to quantify damage in deployed systems in absence of macro-indicators of damage without knowledge of prior stress history. The presented PHM framework is targeted towards high reliability applications such as avionic and space systems. In this paper, Sn3.0Ag0.5Cu alloy packages have been subjected to multiple thermal cycling environments including −55 to 125C and 0 to 100C. Assemblies investigated include area-array packages soldered on FR4 printed circuit cards. The methodology involves the use of condition monitoring devices, for gathering data on damage pre-cursors at periodic intervals. Damage-state interrogation technique has been developed based on the Levenberg-Marquardt Algorithm in conjunction with the microstructural damage evolution proxies. The presented technique is applicable to electronic assemblies which have been deployed on one thermal environment, then withdrawn from service and targeted for redeployment in a different thermal environment. Test cases have been presented to demonstrate the viability of the technique for assessment of prior damage, operational readiness and residual life for assemblies exposed to multiple thermo-mechanical environments. Prognosticated prior damage and the residual life show good correlation with experimental data, demonstrating the validity of the presented technique for multiple thermo-mechanical environments.

Remaining Useful-Life Based on Damage Pre-Cursors for Leadfree Electronics Subjected to Multiple Thermal-Environments

2009 ◽  
Author(s):  
Pradeep Lall ◽  
Rahul Vaidya ◽  
Vikrant More ◽  
Jeff Suhling ◽  
Kai Goebel
Keyword(s):  
Residual Life ◽  
Thermal Environment ◽  
High Reliability ◽  
Remaining Useful Life ◽  
Damage State ◽  
Core System ◽  
Thermal Environments ◽  
Marquardt Algorithm ◽  
Tools And Techniques ◽  
Electronic Assemblies

Electronic assemblies deployed in harsh environments may be subjected to multiple thermal environments during the use-life of the equipment. Often the equipment may not have any macro-indicators of damage such as cracks or delamination. Quantification of thermal environments during use-life is often not feasible because of the data-capture and storage requirements, and the overhead on core-system functionality. There is need for tools and techniques to quantify damage in deployed systems in absence of macro-indicators of damage without knowledge of prior stress history. The presented PHM framework is targeted towards high reliability applications such as avionic and space systems. In this paper, Sn3.0Ag0.5Cu alloy packages have been subjected to multiple thermal cycling environments including −55 to 125C and 0 to 100C. Assemblies investigated include area-array packages soldered on FR4 printed circuit cards. The methodology involves the use of condition monitoring devices, for gathering data on damage pre-cursors at periodic intervals. Damage-state interrogation technique has been developed based on the Levenberg-Marquardt Algorithm in conjunction with the microstructural damage evolution proxies. The presented technique is applicable to electronic assemblies which have been deployed on one thermal environment, then withdrawn from service and targeted for redeployment in a different thermal environment. Test cases have been presented to demonstrate the viability of the technique for assessment of prior damage, operational readiness and residual life for assemblies exposed to multiple thermo-mechanical environments. Prognosticated prior damage and the residual life show good correlation with experimental data, demonstrating the validity of the presented technique for multiple thermo-mechanical environments.

scholarly journals Impacts of Urban Form on Thermal Environment Near the Surface Region at Pedestrian Height: A Case Study Based on High-Density Built-Up Areas of Nanjing City in China

2020 ◽  
Vol 12 (5) ◽  
pp. 1737 ◽  
Author(s):  
Junyan Yang ◽  
Beixiang Shi ◽  
Geyang Xia ◽  
Qin Xue ◽  
Shi-Jie Cao
Keyword(s):  
Urban Form ◽  
Thermal Environment ◽  
Urban Climate ◽  
Urban Canopy ◽  
Surface Region ◽  
High Density ◽  
Average Height ◽  
Near Surface ◽  
Building Density ◽  
Thermal Environments

The continuous worsening of urban thermal environments poses a severe threat to human health and is among the main problems associated with urban climate change and sustainable development. This issue is particularly severe in high-density built-up areas. Existing studies on the thermal environments (temperature data extracted from satellite remote sensing images) are mainly focused on urban canopy areas (airspace below the average height of trees or buildings) rather than the near surface region (at pedestrian height). However, the main outdoor activity space of urban residents is the area near surface region. Hence, this study aims to investigate the influence of urban form (i.e., building density, height, and openness) on thermal environment near the surface region. The high-density built-up areas of a typical megacity (i.e., Nanjing) in China were selected, and the thermal environments of 26 typical blocks were simulated using ENVI-met software. Temperature field measurements were carried out for simulation validation. On this basis, a classified and comparative study was conducted by selecting the key spatial form elements that affect thermal environments. The results showed that in actual high-density built-up areas, single urban form parameter does not determine the thermal environments near the urban surface but mainly affected by the use (function) of space. For this study, the overall thermal environment of a street block is optimal when the building density is between 40% and 50% and the average building height is between 8 and 17 stories. Nonetheless, the urban form can be improved to optimize the overall effects on building functions and thermal environments. Furthermore, function-specific urban form optimization strategies were proposed to optimize thermal environments according to specific functional needs.

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