Heat balance and thermoregulatory responses in pinnaless rabbits

1980 ◽  
Vol 5 (1) ◽  
pp. 37-39 ◽  
Author(s):  
M. Caputa ◽  
W. Kądziela ◽  
J. Narąbski
Keyword(s):  
Heat Balance ◽  
Thermoregulatory Responses

Effect of drinking-water temperature on heat balance and thermoregulatory responses in dairy heifers

1996 ◽  
Vol 47 (4) ◽  
pp. 505 ◽  
Author(s):  
BP Purwanto ◽  
M Harada ◽  
S Yamamoto
Keyword(s):  
Drinking Water ◽  
Water Temperature ◽  
Respiration Rate ◽  
Rectal Temperature ◽  
Heat Balance ◽  
Heat Dissipation ◽  
Environmental Temperature ◽  
Night Time ◽  
Dairy Heifers ◽  
Thermoregulatory Responses

A study was made to determine the effect of heat dissipation from drinking water (8 kg at 10, 20, or 30�C) on the heat balance and thermoregulatory responses of 4 dairy heifers housed at 24, 29, and 34�C. No effect of drinking-water temperature on heat production or heart rate was found. Respiration rate, mean skin-surface temperature, and rectal temperature all decreased with decreasing drinking-water temperature. Rectal temperature reached a minimum 20 min after watering. The respiration rate, skin temperature, and rectal temperature returned to prior-to-watering values 120-180 min after watering. The cooling efficiency of drinking water was about 40%, and decreased at high environmental temperature, because the cooling potential was used initially in depressing heat loss responses. It is suggested that in order to eliminate excessive heat load, chilled drinking water could be effective during the night time when the environmental temperature is lowest.

Role of the sweating from the tail in the thermal balance of the rat-kangaroo Potorous tridactylus

1975 ◽  
Vol 23 (4) ◽  
pp. 453 ◽  
Author(s):  
JW Hudson ◽  
TJ Dawson
Keyword(s):  
Body Temperature ◽  
Heat Balance ◽  
Heat Load ◽  
Thermal Balance ◽  
The Body ◽  
Thermoregulatory Response ◽  
Thermoregulatory Responses ◽  
Air Temperatures ◽  
Potorous Tridactylus

Among the marsupials the thermoregulatory response of sweating is uncommon and has only been described in the larger macropodids. Sweating in kangaroos is very unusual in that it only occurs in response to an exercise heat load. The thermoregulatory responses of a smaller, more generalized rat-kangaroo Potorous tridactylus were therefore examined to obtain a more general appreciation of sweating in macropodids. The pattern of heat balance at low and neutral temperatures was characteristic of that previously found for macropodids; body temperature was 35.9 � 0.52 (mean � se). Standard metabolism was only slightly higher than the predicted level for marsupials and minimal conductance was low, c. 1.3 W m-2 per degree Celsius. At moderate air temperatures heat was primarily lost by vasodilation and panting. The thermoregulatory responses at high air temperatures (near or above body temperature) also included copious sweating from the tail, but not from the body generally. Sweating rates of 600-650 g water per m2 per hour were obtained; these are about twice the generally reported rates for eutherians such as cows and horses.

Selecting the correct exercise intensity for unbiased comparisons of thermoregulatory responses between groups of different mass and surface area

2014 ◽  
Vol 116 (9) ◽  
pp. 1123-1132 ◽  
Author(s):  
Matthew N. Cramer ◽  
Ollie Jay
Keyword(s):  
Surface Area ◽  
Body Mass ◽  
Rectal Temperature ◽  
Heat Production ◽  
Exercise Intensity ◽  
Heat Balance ◽  
Heat Acclimation ◽  
Metabolic Heat ◽  
Thermoregulatory Responses ◽  
Different Levels

We assessed whether comparisons of thermoregulatory responses between groups unmatched for body mass and surface area (BSA) should be performed using a metabolic heat production (Ḣprod) in Watts or Watts per kilogram for changes in rectal temperature (ΔTre), and an evaporative heat balance requirement ( Ereq) in Watts or Watts per square meter for local sweat rates (LSR). Two groups with vastly different mass and BSA [large (LG): 91.5 ± 6.8 kg, 2.12 ± 0.09 m2, n = 8; small (SM): 67.6 ± 5.6 kg, 1.80 ± 0.09 m2, n = 8; P < 0.001], but matched for heat acclimation status, sex, age, and with the same onset threshold esophageal temperatures (LG: +0.37 ± 0.12°C; SM: +0.41 ± 0.17°C; P = 0.364) and thermosensitivities (LG: 1.02 ± 0.54, SM: 1.00 ± 0.38 mg·cm−2·min−1·°C−1; P = 0.918) for sweating, cycled for 60 min in 25°C at different levels of Ḣprod (500 W, 600 W, 6.5 W/kg, 9.0 W/kg) and Ereq (340 W, 400 W, 165 W/m2, 190 W/m2). ΔTre was different between groups at a Ḣprod of 500 W (LG: 0.52 ± 0.15°C, SM: 0.92 ± 0.24°C; P < 0.001) and 600 W (LG: 0.78 ± 0.19°C, SM: 1.14 ± 0.24°C; P = 0.007), but similar at 6.5 W/kg (LG: 0.79 ± 0.21°C, SM: 0.85 ± 0.14°C; P = 0.433) and 9.0 W/kg (LG: 1.02 ± 0.22°C, SM: 1.14 ± 0.24°C; P = 0.303). Furthermore, ΔTre was the same at 9.0 W/kg in a 35°C environment (LG: 1.12 ± 0.30°C, SM: 1.14 ± 0.25°C) as at 25°C ( P > 0.230). End-exercise LSR was different at Ereq of 400 W (LG: 0.41 ± 0.18, SM: 0.57 ± 0.13 mg·cm−2·min−1; P = 0.043) with a trend toward higher LSR in SM at 340 W (LG: 0.28 ± 0.06, SM: 0.37 ± 0.15 mg·cm−2·min−1; P = 0.057), but similar at 165 W/m2 (LG: 0.28 ± 0.06, SM: 0.28 ± 0.12 mg·cm−2·min−1; P = 0.988) and 190 W/m2 (LG: 0.41 ± 0.18, SM: 0.37 ± 0.15 mg·cm−2·min−1; P = 0.902). In conclusion, when comparing groups unmatched for mass and BSA, future experiments can avoid systematic differences in ΔTre and LSR by using a fixed Ḣprod in Watts per kilogram and Ereq in Watts per square meter, respectively.

scholarly journals Running economy, not aerobic fitness, independently alters thermoregulatory responses during treadmill running

2014 ◽  
Vol 117 (12) ◽  
pp. 1451-1459 ◽  
Author(s):  
Jovana Smoljanić ◽  
Nathan B. Morris ◽  
Sheila Dervis ◽  
Ollie Jay
Keyword(s):  
Aerobic Fitness ◽  
Heat Balance ◽  
Physical Characteristics ◽  
Running Economy ◽  
Treadmill Running ◽  
Whole Body ◽  
Maximum Oxygen Consumption ◽  
Running Speed ◽  
Metabolic Heat ◽  
Thermoregulatory Responses

We sought to determine the independent influence of running economy (RE) and aerobic fitness [maximum oxygen consumption (V̇o2max)] on thermoregulatory responses during treadmill running by conducting two studies. In study 1, seven high (HI-FIT: 61 ± 5 ml O2·kg−1·min−1) and seven low (LO-FIT: 45 ± 4 ml O2·kg−1·min−1) V̇o2max males matched for physical characteristics and RE (HI-FIT: 200 ± 21; LO-FIT: 200 ± 18 ml O2·kg−1·km−1) ran for 60 min at 1) 60%V̇o2max and 2) a fixed metabolic heat production (Hprod) of 640 W. In study 2, seven high (HI-ECO: 189 ± 15.3 ml O2·kg−1·km−1) and seven low (LO-ECO: 222 ± 10 ml O2·kg−1·km−1) RE males matched for physical characteristics and V̇o2max (HI-ECO: 60 ± 3; LO-ECO: 61 ± 7 ml O2·kg−1·min−1) ran for 60 min at a fixed 1) speed of 10.5 km/h and 2) Hprod of 640 W. Environmental conditions were 25.4 ± 0.8°C, 37 ± 12% RH. In study 1, at Hprod of 640 W, similar changes in esophageal temperature (ΔTes; HI-FIT: 0.63 ± 0.20; LO-FIT: 0.63 ± 0.22°C; P = 0.986) and whole body sweat losses (WBSL; HI-FIT: 498 ± 66; LO-FIT: 497 ± 149 g; P = 0.984) occurred despite different relative intensities (HI-FIT: 55 ± 6; LO-FIT: 39 ± 2% V̇o2max; P < 0.001). At 60% V̇o2max, ΔTes ( P = 0.029) and WBSL ( P = 0.003) were greater in HI-FIT (1.14 ± 0.32°C; 858 ± 130 g) compared with LO-FIT (0.73 ± 0.34°C; 609 ± 123 g), as was Hprod (HI-FIT: 12.6 ± 0.9; LO-FIT: 9.4 ± 1.0 W/kg; P < 0.001) and the evaporative heat balance requirement (Ereq; HI-FIT: 691 ± 74; LO-FIT: 523 ± 65 W; P < 0.001). Similar sweating onset ΔTes and thermosensitivities occurred between V̇o2max groups. In study 2, at 10.5 km/h, ΔTes (1.16 ± 0.31 vs. 0.78 ± 0.28°C; P = 0.017) and WBSL (835 ± 73 vs. 667 ± 139 g; P = 0.015) were greater in LO-ECO, as was Hprod (13.5 ± 0.6 vs. 11.3 ± 0.8 W/kg; P < 0.001) and Ereq (741 ± 89 vs. 532 ± 130 W; P = 0.007). At Hprod of 640 W, ΔTes ( P = 0.910) and WBSL ( P = 0.710) were similar between HI-ECO (0.55 ± 0.31°C; 501 ± 88 g) and LO-ECO (0.57 ± 0.16°C; 483 ± 88 g), but running speed was different (HI-ECO: 8.2 ± 0.6; LO-ECO: 7.2 ± 0.4 km/h; P = 0.025). In conclusion, thermoregulatory responses during treadmill running are not altered by V̇o2max, but by RE because of differences in Hprod and Ereq.

Analysis of electro- and thermophysical processes occurring during electrocontact baking of flour products.

2020 ◽  
Vol 29 (11) ◽  
pp. 50-55
Author(s):  
V.I. Maklyukov ◽  
◽  
E.O. Gerasimova ◽  
N. V. Labutina ◽  
E.N. Rogozkin ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Theoretical Calculation ◽  
Heat Balance ◽  
Electric Contact ◽  
Wheat Dough ◽  
Baking Process ◽  
Free Moisture ◽  
Contact Heating ◽  
The Heat Balance

The article considers the results of research conducted during electric contact heating of rye-wheat dough pieces. It is established that the electrical conductivity of the crumb dough does not depend on the total humidity of the material, but mainly on the amount of free moisture. Using the current and temperature graphs, you can imagine how free moisture changes during the baking process and the influence of the thermophysical and colloidal process on the change in the value of free moisture. Experimentally determined the amount of heat that is spent on baking 1 kg of bread. The accuracy of the theoretical calculation of this parameter in the heat balance of the baking chamber is confirmed.

Refined thermal calculation of the locomotive heat engine collector

2020 ◽  
pp. 56-58
Author(s):  
P.V. Gubarev ◽  
D.V. Glazunov ◽  
V.G. Ruban ◽  
A.S. Shapshal
Keyword(s):  
Experimental Data ◽  
Electric Motor ◽  
Heat Balance ◽  
Thermal Imaging ◽  
Heat Engine ◽  
Thermal Calculation ◽  
Calculation Results ◽  
Cooling Air ◽  
The Heat Balance ◽  
Traction Electric Motor

The thermal calculation of the locomotive traction engine collector is proposed. The equations of the heat balance of its elements are obtained taking into account the cooling air. The calculation results and experimental data of thermal imaging control are presented. Keywords: traction electric motor, collector, thermal calculation, thermal imaging control. [email protected]

Sign in / Sign up

Export Citation Format

Share Document