Broiler trailer thermal conditions during cold climate transport

2012 ◽  
Vol 92 (2) ◽  
pp. 109-122 ◽  
Author(s):  
N. A. Burlinguette ◽  
M. L. Strawford ◽  
J. M. Watts ◽  
H. L. Classen ◽  
P. J. Shand ◽  
...  
Keyword(s):  
Ambient Temperature ◽  
Thermal Conditions ◽  
Cold Climate ◽  
Ambient Conditions ◽  
Humidity Ratio ◽  
Ambient Temperatures ◽  
Thermal Environments ◽  
Load Volume ◽  
Heat And Moisture ◽  
Roof Vents

Burlinguette, N. A., Strawford, M. L., Watts, J. M., Classen, H. L., Shand, P. J. and Crowe, T. G. 2012. Broiler trailer thermal conditions during cold climate transport. Can. J. Anim. Sci. 92: 109–122. Thermal environments within broiler transport vehicles are dependent on ambient conditions and, if poorly managed, can be a welfare concern. To effectively manage broiler transport, the environmental conditions throughout vehicles must be understood. Under standard commercial practices, temperature and humidity levels in double-trailer broiler vehicles were examined for a range of ambient temperatures (−24 to 11°C). During warmer ambient conditions (9.8°C) trailer roof vents and side curtains were all open, which resulted in a narrowing of the on-board temperature range (10.3 to 16.7°C). As ambient temperature cooled side curtains and some of the roof vents were closed. This resulted in increasingly variable and more extreme thermal conditions, with heat and moisture accumulated along the midline of the load near the front of the lead trailer and near the back of the rear trailer. At an ambient temperature of −22.1°C trailer temperatures ranged from −20.7 to 21.7°C with an estimated 58.6% of the load volume being exposed to temperatures below 0°C. In addition, the trailer humidity ratio rose 14.0 g kg−1 above ambient and conditions approached saturation (RH>80%) in 55.2% of the load volume. These results support the need to find a means to remove moisture and redistribute heat on broiler trailers during cold ambient conditions.

Using Thermoelectric Cooling With Tourniquets for Nerve Preservation

2016 ◽  
Author(s):  
M. Trupiano ◽  
S. Aarabi ◽  
A. F. Emery
Keyword(s):  
Thermal Conditions ◽  
Ambient Conditions ◽  
Transfer Coefficients ◽  
Thermoelectric Coolers ◽  
Ambient Temperatures ◽  
Nerve Preservation ◽  
Heat Transfer Coefficients ◽  
Surface Temperatures ◽  
Element Simulation ◽  
Free And Forced Convection

The use of a tourniquet leads to nerve damage, even if applied for short periods of time. This damage can be minimized if the limb is cooled. Because of the low conductivities of human tissue, core limb cooling is slow unless the surface temperature is very cool. Subzero surface temperatures can lead to skin injury (i.e., frostbite). Ideally one would adjust the limb surface temperatures as a function of time to maximize the cooling rate while avoiding permanent tissue damage. One possible approach is to use a thermoelectric cooler (TEC) in conjunction with a programmable power supply. TEC performance varies strongly with heat absorption rate, a function of limb thermal properties, and hot side temperatures that are strongly affected by the surface conditions on the hot side, i.e., overall heat transfer coefficients and ambient conditions. The paper describes the use of finite element simulation to predict the usefulness of using thermoelectric coolers applied to the surface of a limb when compared to the standard approach of using ice packs. Since the TEC performance is strongly influenced by its warm side thermal conditions, experimental results are presented for different ambient temperatures, free and forced convection, and evaporation of water from a wickable covering.

scholarly journals Performance Analysis of Heat Pump Dryer with Unit-Room in Cold Climate Regions

Energies ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 3125 ◽  
Author(s):  
Yuan ◽  
Lin ◽  
Mao ◽  
Li ◽  
Yang ◽  
...  
Keyword(s):  
Heat Pump ◽  
Ambient Air ◽  
Open Loop ◽  
Cold Climate ◽  
Coefficient Of Performance ◽  
Ambient Conditions ◽  
Total Energy Consumption ◽  
Ambient Temperatures ◽  
Moisture Extraction ◽  
Modelling System

This study presents the development and evaluation of a novel partially open-loop heat pump dryer with a unit-room (HPDU). The unit-room was designed to enable the ambient air to be mixed with the return air, thereby reducing the influence of the ambient air on the system performance, while maintaining a high system thermal efficiency. A modelling system for the HPDU was developed and validated based on a real-scale experimental study. By using the modelling system, the system characteristics under different ambient conditions and bypass factors were analyzed. The energy benefit of the proposed HPDU was quantified through a comparative study with a closed-loop heat pump dryer (CHPD). It is evident that a maximal specific moisture extraction rate (SMER) and a minimal total energy consumption (TEC) existed when changing the bypass factor of the HPDU under certain ambient temperatures. Compared to the CHPD, the coefficient of performance (COP) of the HPDU increased by up to 39.56%, presenting a significant energy benefit for the application of HPDU.

Liver heat production and temperature regulation in the anesthetized dog

1979 ◽  
Vol 237 (5) ◽  
pp. R334-R339 ◽  
Author(s):  
P. Baconnier ◽  
G. Benchetrit ◽  
M. Tanche
Keyword(s):  
Ambient Temperature ◽  
Heat Production ◽  
Linear Correlation ◽  
Temperature Regulation ◽  
Thermal Conditions ◽  
Calorimetric Method ◽  
Ambient Temperatures ◽  
Blood Flows ◽  
Physiological Range ◽  
Negative Linear Correlation

Liver heat production (LHP) was measured in the anesthetized dog by a new calorimetric method. Blood flows and temperatures were measured at the same points. The method avoided damage of liver innervation and vascularization. Changes of LHP were investigated under different thermal conditions. Measurements at controlled arterial temperatures within the physiological range showed changes of LHP when arterial temperature was randomly increased or decreased. When measured LHP was compared in experiments carried out at different ambient temperatures, a negative linear correlation was found between LHP and the ambient temperature. It was concluded that liver heat production may be a factor in temperature regulation.

scholarly journals ENDOTHERMY IN THE SOLITARY BEE ANTHOPHORA PLUMIPES: INDEPENDENT MEASURES OF THERMOREGULATORY ABILITY, COSTS OF WARM-UP AND THE ROLE OF BODY SIZE

1993 ◽  
Vol 174 (1) ◽  
pp. 299-320 ◽  
Author(s):  
G. N. Stone
Keyword(s):  
Ambient Temperature ◽  
Heat Loss ◽  
Body Mass ◽  
Thermal Power ◽  
Thermal Conditions ◽  
Energetic Cost ◽  
Solitary Bee ◽  
Warm Up ◽  
Ambient Temperatures ◽  
Thoracic Temperature

1. This study examines variation in thoracic temperatures, rates of pre-flight warm-up and heat loss in the solitary bee Anthophora plumipes (Hymenoptera; Anthophoridae). 2. Thoracic temperatures were measured both during free flight in the field and during tethered flight in the laboratory, over a range of ambient temperatures. These two techniques give independent measures of thermoregulatory ability. In terms of the gradient of thoracic temperature on ambient temperature, thermoregulation by A. plumipes is more effective before flight than during flight. 3. Warm-up rates and body temperatures correlate positively with body mass, while mass-specific rates of heat loss correlate negatively with body mass. Larger bees are significantly more likely to achieve flight temperatures at low ambient temperatures. 4. Simultaneous measurement of thoracic and abdominal temperatures shows that A. plumipes is capable of regulating heat flow between thorax and abdomen. Accelerated thoracic cooling is only demonstrated at high ambient temperatures. 5. Anthophora plumipes is able to fly at low ambient temperatures by tolerating thoracic temperatures as low as 25 sC, reducing the metabolic expense of endothermic activity. 6. Rates of heat generation and loss are used to calculate the thermal power generated by A. plumipes and the total energetic cost of warm-up under different thermal conditions. The power generated increases with thoracic temperature excess and ambient temperature. The total cost of warm-up correlates negatively with ambient temperature.

Rotary Compressor Performance at Low Ambient Temperatures

2020 ◽  
Vol 28 (04) ◽  
pp. 2050037
Author(s):  
S. Lowrey ◽  
G. Reboux
Keyword(s):  
Ambient Temperature ◽  
Heat Loss ◽  
Heat Pump ◽  
Simulated Data ◽  
Performance Testing ◽  
Rotary Compressor ◽  
Ambient Conditions ◽  
Ambient Temperatures ◽  
Compressor Performance ◽  
Performance Envelope

Small rotary compressors are used in domestic heat pump appliances, for example, in domestic dehumidifiers and heat pump clothes dryers. Compressor performance curves provided by the manufacturer can be based on testing at relatively high ambient temperatures, in some cases as high as 35∘C. This can be much higher compared with the ambient temperature in which the compressor operates when, for example, it is installed in a domestic dehumidifier which can operate in ambient temperatures as low as 10∘C. We have developed a compressor calorimeter to test a small R134a rotary compressor extracted from a commercial domestic dehumidifier and use this to measure compressor performance parameters including the isentropic and volumetric efficiencies and the compressor heat loss fraction. The performance testing has been carried out at ambient temperatures 10∘C, 15∘C, 20∘C and 25∘C for a fixed relative humidity of 70% to compare how the compressor performance varies with the ambient temperature, and to determine how well the compressor performs outside of the performance envelope provided by the manufacturer. The results show that isentropic and volumetric efficiency of these small compressors is relatively insensitive to variation in ambient temperature, even outside of the performance envelope provided by the manufacturer. However, the compressor heat loss fraction can, on average, double from 15% to 30%, between operation at ambient 25∘C and ambient 10∘C. The data obtained in this work is used to construct compressor sub-models for certain ambient temperatures. We show how these sub-models can be used to improve a domestic dehumidifier model for operation at low ambient conditions within the evaporator frosting regime and good agreement is obtained between experimental and simulated data. The authors are not aware of a domestic dehumidifier model designed to work at ambient temperatures within the frosting regime.

scholarly journals Postprandial insulin and nutrient concentrations in lipopolysaccharide-challenged growing pigs reared in thermoneutral and high ambient temperatures1

2019 ◽  
Vol 97 (8) ◽  
pp. 3354-3368
Author(s):  
Paulo Henrique Reis Furtado Campos ◽  
Elodie Merlot ◽  
David Renaudeau ◽  
Jean Noblet ◽  
Nathalie Le Floc’h
Keyword(s):  
Ambient Temperature ◽  
Amino Nitrogen ◽  
Thermal Conditions ◽  
Experimental Period ◽  
Repeated Administration ◽  
Growing Pigs ◽  
Nutrient Concentrations ◽  
Ambient Temperatures ◽  
Lps Challenge ◽  
Postprandial Insulin

Abstract The aim of this study was to evaluate the associated effects of ambient temperature and inflammation caused by repeated administration of Escherichia coli lipopolysaccharide (LPS) on insulin, energy, and AA metabolism. Twenty-eight pigs were assigned to one of the two thermal conditions: thermoneutral (24 °C) or high ambient temperature (30 °C). The experimental period lasted 17 d, which was divided into a 7-d period without LPS (days −7 to −1), and a subsequent 10-d LPS period (days 1 to 10) in which pigs were administered 5 repeated injections of LPS at 2-d intervals. Postprandial profiles of plasma insulin and nutrients were evaluated through serial blood samples taken on days −4 (P0), 4 (P1), and 8 (P2). Before the LPS-challenge (P0), postprandial concentrations of glucose, lactate, Gln, Ile, Leu, Phe, Tyr, and Val were greater in pigs kept at 24 °C than at 30 °C (P < 0.05). In contrast, Arg, Asp, Gly, His, and Met postprandial concentrations at P0 were lower at 24 °C than at 30 °C (P < 0.05). At both 24 and 30 °C conditions, pigs had greater postprandial concentrations of insulin (P < 0.01) and lower concentrations of NEFA (P < 0.01) and α-amino nitrogen (P < 0.05) at P1 and P2 than at P0. Compared with P0, postprandial concentrations of glucose were greater (P < 0.05) at P1 in pigs kept at 24 °C, and at P1 and P2 in pigs kept at 30 °C. At both ambient temperatures, pigs had lower (P < 0.05) postprandial concentrations of Ala, Gly, His, Ile, Leu, Pro, Ser, Thr, Trp, and Val at P1 and P2 than at P0. Arginine postprandial concentration at P1 was lower than at P0 in pigs kept at 24 °C (P < 0.05), whereas no difference was observed in pigs at 30 °C. Relative to P0, Gln and Tyr concentrations were lower at P1 and P2 in pigs kept at 24 °C (P < 0.01), whereas lower Gln concentration was observed only at P2 (P < 0.01) and lower Tyr only at P1 (P < 0.01) in pigs kept at 30 °C. Our study shows a hyperglycemic and hyperinsulinemic state in LPS-challenged pigs and a greater magnitude of this response in pigs kept at 30 °C. Furthermore, LPS caused important changes in BCAA, His, Thr, and Trp profiles, suggesting the role these AA in supporting the inflammatory response. Finally, our results suggest that LPS-induced effects on postprandial profiles of specific AA (Arg, Gln, Phe, and Tyr) may be modulated by ambient temperature.

scholarly journals The Supraclavicular Skin Temperature Response to Mild Cold Stimulation is Dependent on Ambient Temperature

2019 ◽  
pp. 1-5
Author(s):  
Michael E. Symonds ◽  
Helen Budge ◽  
I A Macdonald ◽  
Lindsay Jane Robinson
Keyword(s):  
Ambient Temperature ◽  
Skin Temperature ◽  
Cold Exposure ◽  
Temperature Response ◽  
Ambient Conditions ◽  
Wireless Data ◽  
Cold Stimulation ◽  
Ambient Temperatures ◽  
Brown Adipose ◽  
Supraclavicular Skin Temperature

Purpose: This study investigated the basal activity, and cold-induced thermogenic response, of supraclavicular brown adipose tissue (BAT) under warm (23˚C) and cool (18˚C) ambient conditions using supraclavicular skin temperature as a measure of BAT activity. As a highly metabolic, heat-producing tissue, it has been hypothesised that under-active/dysfunctional BAT may underlie a pathological energy imbalance leading to obesity. Methods: Five lean, healthy participants underwent infrared thermography (IRT) of supraclavicular BAT before, and during, mild cold exposure (single-hand immersion in cool water at 20˚C), once at 18˚C and once at 23˚C. Energy expenditure (EE) was measured simultaneously using indirect calorimetry, and mean skin temperature (TMSK) was calculated at 1-minute intervals in parallel to IRT using wireless data loggers. Results: Following 30 minutes of hand cooling, supraclavicular skin temperature (TSCR) rose significantly from baseline at an ambient temperature of 23˚C (∆TSCR: 0.17 ± 0.03˚C, P < 0.01), and EE rose by 0.22 ± 0.02 kJ/min, P < 0.001. At an ambient room temperature of 18˚C, TSCR after hand cooling was similar to baseline, and EE remained unchanged. The TMSK response was indicative of a systemic vasoconstrictive response of similar magnitude in both warm and cool ambient temperatures. Conclusions: At 18˚C in light clothing, BAT may already be maximally stimulated at baseline, and respond minimally to additional cold exposure. Ambient temperature is recognised as a determinant of glucose uptake in BAT. In this study, we show, that it also modulates the TSCR response to further localised cold-stimulation, indicating an effect on BAT thermogenesis.

Ambient temperature and annual timing affect torpor bouts and euthermic phases of hibernating European ground squirrels (Spermophilus citellus)

2009 ◽  
Vol 87 (3) ◽  
pp. 204-210 ◽  
Author(s):  
István Németh ◽  
Viktor Nyitrai ◽  
Vilmos Altbäcker
Keyword(s):  
Ambient Temperature ◽  
Thermal Conditions ◽  
Ground Squirrels ◽  
Typical Pattern ◽  
Internal Factors ◽  
Ambient Temperatures ◽  
Timing Effect ◽  
Temperature State ◽  
Timing Pattern ◽  
Spermophilus Citellus

The low body temperature state of hibernating mammals is interrupted regularly by short euthermic phases. The frequency of these euthermic phases changes according to the phase of hibernation. This typical pattern, common among ground squirrels (genus Spermophilus F. Cuvier, 1825), can be regulated by internal factors and affected by outside temperature. To evaluate the effects of internal annual timing and ambient temperature, we monitored nest temperatures of overwintering European ground squirrels ( Spermophilus citellus (L., 1766)) under three temperature conditions during late hibernation (9, 5, 0 °C). Our results showed that in spite of constant thermal conditions, an annual timing effect changed torpor-bout length (TBL) at 9 and 5 °C but not at 0 °C. Ambient temperature had an independent influence on TBL and euthermic phases. The loss in body mass was higher at higher ambient temperatures and was affected by TBL and euthermic phases. Thus, the hibernation pattern of European ground squirrels is regulated by both an annual timing pattern and the ambient temperature in the hibernacula.

The free-convective anomaly

1999 ◽  
Vol 87 (1) ◽  
pp. 54-73 ◽  
Author(s):  
Robert G. Steadman
Keyword(s):  
Thermal Environment ◽  
Apparent Temperature ◽  
Heat Index ◽  
Vapor Pressures ◽  
Ambient Conditions ◽  
Three Solutions ◽  
Ambient Temperatures ◽  
The One ◽  
Heat And Moisture ◽  
The Heat Balance

Persons exposed to high temperature, or to equivalent environmental factors, have quantifiable reactions, such as reducing the resistance to both heat and moisture flow in skin tissues and clothing needed to maintain thermal equilibrium. The one-to-one relationship between this resistance in the walking person and temperature, with the other factors neutral, is the basis for the apparent temperature scale and the derived heat index. When this approach is taken to assess the thermal environment for a still person exposed to heat in still air, there is a zone of ambient conditions in which there are three solutions to the heat-balance equation. Extraordinary thermal stress occurs, depending slightly on other conditions, at ambient temperatures near 41°C, especially at high humidity, because of the difficulty in carrying sweat vapor from the person when free convection is minimal. This anomaly is examined for a range of ambient vapor pressures and extra radiation. The rapid rise in heat stress when ambient temperature just exceeds body temperature in still conditions may explain the severity of some observed distress.

Effect of Ambient Temperature on Calibration of Cooled Thermal Camera

2017 ◽  
Vol 67 (2) ◽  
pp. 173
Author(s):  
Amit Kumar Sharma ◽  
Sanjay Kumar Sharma ◽  
Prashant Vasistha ◽  
Jagdish Prasad Mangalhara
Keyword(s):  
Measurement Error ◽  
Ambient Temperature ◽  
Temperature Measurement ◽  
Ambient Conditions ◽  
Thermal Camera ◽  
Environmental Chamber ◽  
Ambient Temperatures ◽  
Acceptable Accuracy ◽  
Thermal Cameras ◽  
Extended Area

<p>Thermal cameras may be used under ambient conditions that differ significantly from the calibration conditions. The effect of ambient temperature on temperature measurement error is examined for MWIR and LWIR cooled thermal cameras. The facilities used include an environmental chamber and an extended area blackbody with temperature controller. Significant differences were observed in the temperatures measured by the cameras placed in different ambient temperatures, with reference to the set blackbody temperatures. Re-calibration was done to account for variations in ambient temperature from 5 ºC to on the outputs of the cameras. It was found that after such recalibration, the measurement error was within acceptable accuracy of ±1 °C.</p>

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