Prediction of Optimum Supplemental Heat for Piglets

2019 ◽  
Vol 62 (2) ◽  
pp. 321-342 ◽  
Author(s):  
Hugo F. M. Milan ◽  
Alex Sandro Campos Maia ◽  
Kifle G. Gebremedhin
Keyword(s):  
Energy Balance ◽  
Skin Temperature ◽  
Air Temperature ◽  
Computational Models ◽  
Thermal Environment ◽  
Learning System ◽  
Mechanistic Models ◽  
Neutral Zone ◽  
Hair Coat ◽  
System Parameters

Abstract. The thermal environment of farrowing facilities is generally controlled at the thermo-neutral zone for sows (15°C to 19°C). This imposes thermal challenges for newborn piglets, which are thermally comfortable at temperatures 10°C to 20°C higher (32°C to 35°C). To satisfy the energetic requirements of piglets, supplemental heat is installed in creep or brooder areas. In this study, we determined optimum supplemental heat requirements (supplied by heating lamps) for piglets based on energy balance as a function of air temperature and animal body weight. We also determined the zone of least thermoregulation of piglets for a given weight when supplemental heat is not provided. Energy balance was calculated using an ensemble of mechanistic models of bio-heat transfer that predicts hair-coat temperature, skin temperature, and skin heat flux. Inputs to the ensemble of mechanistic models include air temperature, black-globe temperature, rectal temperature, and system parameters (e.g., thickness of internal tissues and thermal conductivities). Input temperatures were predicted from measured air temperature in the pen and supplemental heat using machine learning. System parameters were measured or obtained from the literature and optimized using the Monte Carlo method. Ensemble predictions of hair-coat and skin temperature agreed within 3.5% with measured data. The ensemble-predicted zone of least thermoregulation agreed well with previous reports. Predicted optimum supplemental heat showed an exponential decay trend with increasing air temperature and/or animal weight. For air temperature between 15°C and 19°C, the predicted optimum supplemental heat was 266 to 344 W and 44 to 128 W for piglets weighing 1 kg and 20 kg, respectively. The predicted optimum supplemental heat was ~200 W lower for piglets at the end of the farrowing cycle (assuming weight of 20 kg) than at birth (assuming birth weight of 1 kg). Keywords: Bio-heat equation, Computational models, Ensemble learning, Piglets, Precision livestock farming, Supplemental heat, Thermo-neutral zone.

scholarly journals Assessment of Thermal Environment in a Kitchen with a New Ventilation System

2019 ◽  
Vol 111 ◽  
pp. 02034 ◽  
Author(s):  
Sumei Liu ◽  
Xiaojie Zhou ◽  
Xuan Liu ◽  
Xiaorui Lin ◽  
Ke Qing ◽  
...  
Keyword(s):  
Skin Temperature ◽  
Air Temperature ◽  
Indoor Air ◽  
Thermal Environment ◽  
Thermal Sensation ◽  
Ventilation System ◽  
Great Influence ◽  
Comfort Level ◽  
Whole Body ◽  
Body Parts

Chinese kitchen environment is usually hot and humid in summer and cold in winter, while housewife spends considerable time there. This investigation developed a new ventilation system for Chinese kitchens to improve thermal comfort level. To assess the thermal performance of the ventilation system, 32 cooks were asked to prepare the same dishes in the kitchen with or without the system in summer in Changsha, China. The assessment was carried out by subjective questionnaire survey on thermal sensation vote (TSV) and objective on-site measurements of the indoor air temperature and cook’s skin temperature. The indoor air temperature was measured at different locations in the kitchen. The skin temperature was measured at 18 body parts of the cooks. The results show that the thermal environment in the kitchen was non-uniform and local thermal sensation had a great influence on the whole body sensation. Without the new ventilation system, the cooks complained that the hottest parts were thorax, head and face areas. Reasonably good correlation existed between the cooks’ skin temperatures and their thermal sensation votes. The increase of cooks’ skin temperature with the ventilation system was lower than that without the ventilation system. TSV was improved with the new ventilation system.

scholarly journals Effect of the Silvopastoral System on the Thermal Comfort of Lambs in a Subtropical Climate: A Preliminary Study

Agriculture ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 790
Author(s):  
Frederico Márcio C. Vieira ◽  
Jaqueline Agnes Pilatti ◽  
Zilmara Maria Welfer Czekoski ◽  
Vinicius F. C. Fonsêca ◽  
Piotr Herbut ◽  
...  
Keyword(s):  
Surface Temperature ◽  
Air Temperature ◽  
Heat Load ◽  
Thermal Environment ◽  
Ground Surface ◽  
Radiant Heat ◽  
Silvopastoral System ◽  
Hair Coat ◽  
Ground Surface Temperature ◽  
Preliminary Study

The silvopastoral system has the potential to alleviate the negative impacts of heat stress on livestock. Through a preliminary study, we assessed the thermal environment experienced by hair coat lambs, as well as the impacts on their bio-thermal and behavioural responses, when either kept in either the silvopastoral system, or exposed to full sun. Twelve hair coat lambs (Dorper × Santa Ines) were randomly assigned to a silvopastoral system or full sun exposure during the summer (from January to February 2017). Parameters, including air temperature, black globe temperature, relative humidity, wind speed, and ground surface temperature, were measured daily for both thermal environments. From 14:00 to 16:00, lambs kept in silvopastoral areas experienced lower levels of air temperature, radiant heat load, and ground surface temperature. Consequently, they had a lower hair coat surface and lower body rectal temperatures. Lambs exposed to a shaded environment spent more time grazing and walking, and less time standing at rest. In conclusion, lambs kept in a silvopastoral system experienced lower levels of radiant heat load and ground surface temperature. In addition, the animals showed a reduced requirement for evaporative cooling and expressed behaviours that indicated a comfortable thermal environment.

scholarly journals Response of the Energy Balance on the Margin of the Greenland Ice Sheet to Temperature Changes

1990 ◽  
Vol 36 (123) ◽  
pp. 217-221 ◽  
Author(s):  
Roger J. Braithwaite ◽  
Ole B. Olesen
Keyword(s):  
Heat Flux ◽  
Energy Balance ◽  
Air Temperature ◽  
Sensible Heat Flux ◽  
Ice Sheet ◽  
Temperature Response ◽  
Greenland Ice Sheet ◽  
Energy Balance Model ◽  
Balance Model ◽  
Sensible Heat

AbstractDaily ice ablation on two outlet glaciers from the Greenland ice sheet, Nordbogletscher (1979–83) and Qamanârssûp sermia (1980–86), is related to air temperature by a linear regression equation. Analysis of this ablation-temperature equation with the help of a simple energy-balance model shows that sensible-heat flux has the greatest temperature response and accounts for about one-half of the temperature response of ablation. Net radiation accounts for about one-quarter of the temperature response of ablation, and latent-heat flux and errors account for the remainder. The temperature response of sensible-heat flux at QQamanârssûp sermia is greater than at Nordbogletscher mainly due to higher average wind speeds. The association of high winds with high temperatures during Föhn events further increases sensible-heat flux. The energy-balance model shows that ablation from a snow surface is only about half that from an ice surface at the same air temperature.

Toe Temperatures During Dartmoor Training

1988 ◽  
Vol 74 (3) ◽  
pp. 181-186
Author(s):  
S. P. L. Travis
Keyword(s):  
Surface Temperature ◽  
Ambient Temperature ◽  
Skin Temperature ◽  
Air Temperature ◽  
Factors Associated ◽  
Recording Period ◽  
Exposure To Cold ◽  
Main Factors ◽  
Minimum Air Temperature

AbstractThe surface temperature of eight Royal Marine recruits was monitored in the field during Autumn training on Dartmoor (minimum air temperature 4.5°C). The lowest skin temperature recorded was 6.1°C. One subject experienced a toe temperature below 10° for 5.5 hours and below 15°C for 12.6 hours during a 24 hour recording period. Ambient temperature and inactivity during exposure to cold were the main factors associated with low toe temperatures but individual responses varied widely.

scholarly journals The Street Air Warming Phenomenon in a High-Rise Compact City

Atmosphere ◽  
2018 ◽  
Vol 9 (10) ◽  
pp. 402 ◽  
Author(s):  
Xiaoxue Wang ◽  
Yuguo Li ◽  
Xinyan Yang ◽  
Pak Chan ◽  
Janet Nichol ◽  
...  
Keyword(s):  
Thermal Comfort ◽  
Air Temperature ◽  
Thermal Environment ◽  
Urban Climate ◽  
Pollutant Dispersion ◽  
Urban Morphology ◽  
Air Temperatures ◽  
Significant Difference ◽  
Sensitivity Studies ◽  
Weather Stations

The street thermal environment is important for thermal comfort, urban climate and pollutant dispersion. A 24-h vehicle traverse study was conducted over the Kowloon Peninsula of Hong Kong in summer, with each measurement period consisting of 2–3 full days. The data covered a total of 158 loops in 198 h along the route on sunny days. The measured data were averaged by three methods (direct average, FFT filter and interpolated by the piecewise cubic Hermite interpolation). The average street air temperatures were found to be 1–3 °C higher than those recorded at nearby fixed weather stations. The street warming phenomenon observed in the study has substantial implications as usually urban heat island (UHI) intensity is estimated from measurement at fixed weather stations, and therefore the UHI intensity in the built areas of the city may have been underestimated. This significant difference is of interest for studies on outdoor air temperature, thermal comfort, urban environment and pollutant dispersion. The differences were simulated by an improved one-dimensional temperature model (ZERO-CAT) using different urban morphology parameters. The model can correct the underestimation of street air temperature. Further sensitivity studies show that the building arrangement in the daytime and nighttime plays different roles for air temperature in the street. City designers can choose different parameters based on their purpose.

scholarly journals The interrelationship between air temperature and humidity as applied locally to the skin: The resultant response on skin temperature and blood flow with age differences

2012 ◽  
Vol 18 (4) ◽  
pp. CR201-CR208 ◽  
Author(s):  
Jerrold S. Petrofsky ◽  
Lee Berk ◽  
Faris Alshammari ◽  
Haneul Lee ◽  
Adel Hamdan ◽  
...  
Keyword(s):  
Blood Flow ◽  
Skin Temperature ◽  
Age Differences ◽  
Air Temperature ◽  
Temperature And Humidity

scholarly journals Energy-saving potential of intermittent heating system: Influence of composite phase change wall and optimization strategy

2020 ◽  
pp. 014459872096921
Author(s):  
Yanru Li ◽  
Enshen Long ◽  
Lili Zhang ◽  
Xiangyu Dong ◽  
Suo Wang
Keyword(s):  
Energy Consumption ◽  
Thermal Comfort ◽  
Phase Change ◽  
Air Temperature ◽  
Indoor Air ◽  
Thermal Environment ◽  
Optimization Strategy ◽  
Indoor Thermal Environment ◽  
Indoor Thermal Comfort ◽  
Intermittent Heating

In the Yangtze River zone of China, the heating operation in buildings is mainly part-time and part-space, which could affect the indoor thermal comfort while making the thermal process of building envelope different. This paper proposed to integrate phase change material (PCM) to building walls to increase the indoor thermal comfort and attenuate the temperature fluctuations during intermittent heating. The aim of this study is to investigate the influence of this kind of composite phase change wall (composite-PCW) on the indoor thermal environment and energy consumption of intermittent heating, and further develop an optimization strategy of intermittent heating operation by using EnergyPlus simulation. Results show that the indoor air temperature of the building with the composite-PCW was 2–3°C higher than the building with the reference wall (normal foamed concrete wall) during the heating-off process. Moreover, the indoor air temperature was higher than 18°C and the mean radiation temperature was above 20°C in the first 1 h after stopping heating. Under the optimized operation condition of turning off the heating device 1 h in advance, the heat release process of the composite-PCW to the indoor environment could maintain the indoor thermal environment within the comfortable range effectively. The composite-PCW could decrease 4.74% of the yearly heating energy consumption compared with the reference wall. The optimization described can provide useful information and guidance for the energy saving of intermittently heated buildings.

scholarly journals Near–surface air temperature and snow skin temperature comparison from CREST-SAFE station data with MODIS land surface temperature data

2015 ◽  
Vol 12 (8) ◽  
pp. 7665-7687 ◽  
Author(s):  
C. L. Pérez Díaz ◽  
T. Lakhankar ◽  
P. Romanov ◽  
J. Muñoz ◽  
R. Khanbilvardi ◽  
...  
Keyword(s):  
Surface Temperature ◽  
Skin Temperature ◽  
Air Temperature ◽  
Land Surface Temperature ◽  
Land Surface ◽  
Hydrological Cycle ◽  
Critical Role ◽  
Surface Air Temperature ◽  
Balance Model ◽  
Near Surface

Abstract. Land Surface Temperature (LST) is a key variable (commonly studied to understand the hydrological cycle) that helps drive the energy balance and water exchange between the Earth's surface and its atmosphere. One observable constituent of much importance in the land surface water balance model is snow. Snow cover plays a critical role in the regional to global scale hydrological cycle because rain-on-snow with warm air temperatures accelerates rapid snow-melt, which is responsible for the majority of the spring floods. Accurate information on near-surface air temperature (T-air) and snow skin temperature (T-skin) helps us comprehend the energy and water balances in the Earth's hydrological cycle. T-skin is critical in estimating latent and sensible heat fluxes over snow covered areas because incoming and outgoing radiation fluxes from the snow mass and the air temperature above make it different from the average snowpack temperature. This study investigates the correlation between MODerate resolution Imaging Spectroradiometer (MODIS) LST data and observed T-air and T-skin data from NOAA-CREST-Snow Analysis and Field Experiment (CREST-SAFE) for the winters of 2013 and 2014. LST satellite validation is imperative because high-latitude regions are significantly affected by climate warming and there is a need to aid existing meteorological station networks with the spatially continuous measurements provided by satellites. Results indicate that near-surface air temperature correlates better than snow skin temperature with MODIS LST data. Additional findings show that there is a negative trend demonstrating that the air minus snow skin temperature difference is inversely proportional to cloud cover. To a lesser extent, it will be examined whether the surface properties at the site are representative for the LST properties within the instrument field of view.

Sign in / Sign up

Export Citation Format

Share Document