The influence of age, wind speed and ambient temperature on nonevaporative heat loss in turkeys (Meleagris gallopavo)

1989 ◽  
Vol 14 (3) ◽  
pp. 139-145 ◽  
Author(s):  
A. Burmeister ◽  
M. Jurkschat ◽  
M. Nichelmann ◽  
T. Postel
2019 ◽  
Vol 142 (2) ◽  
Author(s):  
Xiaotao Zheng ◽  
Xiaohai Zhang ◽  
Jiuyang Gao ◽  
Linwei Ma ◽  
Wei Wang ◽  
...  

Abstract Sealing performance and heat loss are important factors for pipe flange joints (PFJs) subjected to medium or high temperatures. Heat loss is of great interest in practical engineering for uninsulated PFJs. Since an insulation layer may degrade the sealing performance of PFJs, heat loss of PFJs was tested and simulated considering various ambient temperatures of −10 °C, 0 °C, 10 °C, 20 °C, 30 °C, and 40 °C, with wind speeds of 0 m/s and 3 m/s and flange joint target temperatures of 200 °C, 300 °C, and 400 °C. It is worth noting that the experiments were performed during summer for high ambient temperatures and during winter for low ambient temperatures. As expected, the steady temperature slightly increases with the increase of external ambient temperature. For the same flange joint temperature, a 3 m/s wind speed decreases significantly the steady temperature, especially when the higher target temperature is applied. If the external wind speed is 3 m/s and the flange joint target temperatures are 200 °C, 300 °C, and 400 °C, respectively, the heat loss increases by approximately 38.4%, 30.7% and 23.6% when the ambient temperature changes from 30 °C to 10 °C. Moreover, the simulated temperatures agree well with the tested temperatures in most cases, and the average error is approximately 8%. The energy saving efficiency under the windless condition is approximately on average 26% higher than that with a wind speed of 3 m/s.


2022 ◽  
Vol 0 (0) ◽  
Author(s):  
Qusay Hassan ◽  
Saadoon Abdul Hafedh ◽  
Ali Hasan ◽  
Marek Jaszczur

Abstract The study evaluates the visibility of solar photovoltaic power plant construction for electricity generation based on a 20 MW capacity. The assessment was performed for four main cities in Iraq by using hourly experimental weather data (solar irradiance, wind speed, and ambient temperature). The experimental data was measured for the period from 1st January to 31st December of the year 2019, where the simulation process was performed at a 1 h time step resolution at the same resolution as the experimental data. There are two positionings considered for solar photovoltaic modules: (i) annual optimum tilt angle and (ii) two-axis tracking system. The effect of the ambient temperature and wind on the overall system energy generated was taken into consideration. The study is targeted at evaluating the potential solar energy in Iraq and the viability of electricity generation using a 20 MW solar photovoltaic power plant. The results showed that the overall performance of the suggested power plant capacity is highly dependent on the solar irradiance intensity and the ambient temperature with wind speed. The current 20 MW solar photovoltaic power plant capacity shows the highest energy that can be generated in the mid-western region and the lowest in the northeast regions. The greatest influence of the ambient temperature on the energy genrated by power plants is observed in the southern regions.


1965 ◽  
Vol 20 (4) ◽  
pp. 796-801 ◽  
Author(s):  
R. T. Tregear

The heat loss from excised pelts of rabbits, horses, and pigs has been measured at various wind speeds. The temperature gradient through the fur was also measured. The thermal insulation of fur is highly dependent on the hair density (i.e., number of hairs/ cm2), and on the wind passing over its surface. If there are less than 1,000 hairs/cm2, an 8-mph wind penetrates deep into the fur, but at higher hair densities an 18-mph wind penetrates only a little way into the fur. fur insulation; obstruction of wind by hair Submitted on September 10, 1964


2018 ◽  
Vol 32 (1) ◽  
pp. 60-68 ◽  
Author(s):  
Sai Nyan Lin Tun ◽  
Than Htut Aung ◽  
Aye Sandar Mon ◽  
Pyay Hein Kyaw ◽  
Wattasit Siriwong ◽  
...  

Purpose Dust (particulate matters) is very dangerous to our health as it is not visible with our naked eyes. Emissions of dust concentrations in the natural environment can occur mainly by road traffic, constructions and dust generating working environments. The purpose of this paper is to assess the ambient dust pollution status and to find out the association between PM concentrations and other determinant factors such as wind speed, ambient temperature, relative humidity and traffic congestion. Design/methodology/approach A cross-sectional study was conducted for two consecutive months (June and July, 2016) at a residential site (Defence Services Liver Hospital, Mingaladon) and a commercial site (Htouk-kyant Junction, Mingaladon) based on WHO Air Quality Reference Guideline Value (24-hour average). Hourly monitoring of PM2.5 and PM10 concentration and determinant factors such as traffic congestion, wind speed, ambient temperature and relative humidity for 24 hours a day was performed in both study sites. CW-HAT200 handheld particulate matters monitoring device was used to assess PM concentrations, temperature and humidity while traffic congestion was monitored by CCTV cameras. Findings The baseline PM2.5 and PM10 concentrations of Mingaladon area were (28.50±11.49)µg/m3 and (52.69±23.53)µg/m3, means 61.48 percent of PM2.5 concentration and 54.92 percent of PM10 concentration exceeded than the WHO reference value during the study period. PM concentration usually reached a peak during early morning (within 3:00 a.m.-5:00 a.m.) and at night (after 9:00 p.m.). PM2.5 concentration mainly depends on traffic congestion and temperature (adjusted R2=0.286), while PM10 concentration depends on traffic congestion and relative humidity (adjusted R2=0.292). Wind speed played a negative role in both PM2.5 and PM10 concentration with r=−0.228 and r=−0.266. Originality/value The air quality of the study area did not reach the satisfiable condition. The main cause of increased dust pollution in the whole study area was high traffic congestion (R2=0.63 and 0.60 for PM2.5 and PM10 concentration).


1979 ◽  
Vol 80 (1) ◽  
pp. 217-229 ◽  
Author(s):  
HEINRICH BERND

1. While foraging, attacking, or leaving or returning to their hives, both the African and European honeybees maintained their thoracic temperature at 30 °C or above, independent of ambient temperature from 7 to 23 °C (in shade). 2. Thoracic temperatures were not significantly different between African and European bees. 3. Thoracic temperatures were significantly different during different activities. Average thoracic temperatures (at ambient temperatures of 8–23 °C) were lowest (30 °C) in bees turning to the hive. They were 31–32 °C during foraging, and 36–38 °C in bees leaving the hive, and in those attacking. The bees thus warm up above their temperature in the hive (32 °C) before leaving the colony. 4. In the laboratory the bees (European) did not maintain the minimum thoracic temperature for continuous flight (27 °C) at 10 °C. When forced to remain in continuous flight for at least 2 min, thoracic temperature averaged 15 °C above ambient temperature from 15 to 25 °C, and was regulated only at high ambient temperatures (30–40 °C). 5. At ambient temperatures > 25 °C, the bees heated up during return to the hive, attack and foraging above the thoracic temperatures they regulated at low ambient temperatures to near the temperatures they regulated during continuous flight. 6. In both African and European bees, attack behaviour and high thoracic temperature are correlated. 7. The data suggest that the bees regulate thoracic temperature by both behavioural and physiological means. It can be inferred that the African bees have a higher metabolic rate than the European, but their smaller size, which facilitates more rapid heat loss, results in similar thoracic temperatures.


1959 ◽  
Vol 14 (3) ◽  
pp. 387-389 ◽  
Author(s):  
Robert B. Payne

An experiment was conducted for the purpose of learning a) whether or not performance decrement in monitoring and controlling a complex visual display is related to body heat loss and b) whether or not such an impairment can be forestalled by glycine administration. Following extensive training on the experimental task, 72 subjects were independently and randomly assigned to the 9 combinations of 3 ambient temperature conditions (70°, 55° and 40℉) and 3 glycine treatments (0, 20 and 40 gm), then required to execute a performance sequence lasting 3 hours and 20 minutes. Statistical analyses established that the mathematical function relating performance to temperature was a parabola having a maximum near 55°. No significant glycine effects were observed. Submitted on September 25, 1958


1996 ◽  
Vol 37 (3) ◽  
pp. 501-520 ◽  
Author(s):  
B. Tzschentke ◽  
M. Nichelmann ◽  
T. Postel

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