scholarly journals Emperor penguin body surfaces cool below air temperature

2013 ◽  
Vol 9 (3) ◽  
pp. 20121192 ◽  
Author(s):  
D. J. McCafferty ◽  
C. Gilbert ◽  
A.-M. Thierry ◽  
J. Currie ◽  
Y. Le Maho ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Loss ◽  
Thermal Imaging ◽  
Skin Surface ◽  
The Body ◽  
Emperor Penguin ◽  
Emperor Penguins ◽  
Heat Transfer Theory ◽  
Terre Adélie ◽  
Sky Conditions

Emperor penguins Aptenodytes forsteri are able to survive the harsh Antarctic climate because of specialized anatomical, physiological and behavioural adaptations for minimizing heat loss. Heat transfer theory predicts that metabolic heat loss in this species will mostly depend on radiative and convective cooling. To examine this, thermal imaging of emperor penguins was undertaken at the breeding colony of Pointe Géologie in Terre Adélie (66°40′ S 140° 01′ E), Antarctica in June 2008. During clear sky conditions, most outer surfaces of the body were colder than surrounding sub-zero air owing to radiative cooling. In these conditions, the feather surface will paradoxically gain heat by convection from surrounding air. However, owing to the low thermal conductivity of plumage any heat transfer to the skin surface will be negligible. Future thermal imaging studies are likely to yield further insights into the adaptations of this species to the Antarctic climate.

scholarly journals INSTALLATION FOR DETERMINATION OF HEAT RELEASE OF HEATING RADIATORS

2021 ◽  
Vol 4 (164) ◽  
pp. 77-81
Author(s):  
Yu. Ivashina ◽  
V. Zavodyannyi
Keyword(s):  
Heat Transfer ◽  
Heat Loss ◽  
Electrical Power ◽  
Electric Heating ◽  
Middle Part ◽  
Heat Losses ◽  
The Body ◽  
Heat Output ◽  
Stationary Mode

To calculate the share of thermal energy consumed by this apartment in an apartment building, it is necessary to determine the heat transfer of all heating radiators in the house. But the heat transfer given in the passport of the heating device corresponds to the temperature pressure equal to 70K. Often the owners install non-standard devices, so the problem of determining the heat transfer of heating radiators in real conditions is relevant. Thermometric method, which is called electric, is widely used for laboratory determination of heat transfer of heating devices. Water by means of the pump circulates through an electric copper and the investigated radiator. The heat output of the latter is defined as the difference between the supplied electrical power (boiler power plus pump) and heat loss. The purpose of the work is to develop and study the operation of the installation for determining the heat transfer of heating radiators, which had a simpler design and could ensure proper measurement accuracy. We have proposed a scheme and design of the installation for determining the heat transfer of electric heating radiators, which differs in that it does not include a circulating pump. Water in the system circulates under the action of gravity due to changes in the density of the coolant during heating and cooling. This greatly simplifies the circuit by eliminating not only the pump but also the valve and the air outlet valve. The heater chamber is made of a steel pipe with a diameter of 88 mm. A steel cover is attached to the lower flange, through which a 1-1.5 kW heater is introduced into the chamber. Two 1/2 ″ sections of pipe are welded to the body of the heater chamber, through which the radiator is connected by means of rubber couplings. The cylindrical surface of the chamber on top of the layer of internal insulation is covered with a shielding heater, the temperature of which is maintained equal to the surface temperature of the heater chamber in the middle part. A layer of external thermal insulation is installed on top of the shielding heater. To determine heat loss, the radiator is disconnected from the heater chamber, plugs are installed and insulated. In stationary mode, the dependence of the heater power on the temperature of the heater chamber is measured, which determines the power of heat losses. The simplification of the installation has led not only to its reduction in price, but also to an increase in accuracy due to the reduction of heat losses and the simplicity of their definition.

Analysis of Heat Loss of Ground Pipeline of Thermal Production Oilfield

2011 ◽  
Vol 90-93 ◽  
pp. 3057-3060 ◽  
Author(s):  
Jian Jun Liu ◽  
Gui Hong Pei ◽  
You Jun Ji
Keyword(s):  
Heat Transfer ◽  
Layer Thickness ◽  
Heat Loss ◽  
Thermal Insulation ◽  
Oil Recovery ◽  
Heavy Oil ◽  
Insulation Layer ◽  
Obvious Effect ◽  
Steam Pipeline ◽  
Heat Transfer Theory

Steam stimulation is one of the main methods used in heavy oil reservoir development. How to inject high temperature and high dryness steam is a key factor to enhance heavy oil recovery. It is significant to evaluate heat transfer of steam pipeline and optimize thermal insulation layer for heavy oil exploitation. Based on fluid mechanics, heat transfer theory, considered phase change, mathematical model to calculate heat transfer and heat loss of steam pipeline was derived. Using COMSOL Multiphysics, a finite element based program for simulating unlimited multiphysics and single physics applications, the author simulated heat transferring in ground steam pipeline and analyzed the effect of thermal insulation layer. From the simulation results, it was known that, (1) Along with the pipeline distance increases, the steam dryness decreases, the decrease rate decreases with the distance increases. (2) At the same transmission distance, the bigger the thermal insulation layer thickness is, the smaller the heat loss of the steam is. The heat loss of steam transmission mainly center on the first half pipeline. (3) With the thickness of thermal insulation layer increases, the heatloss declines. After the thickness of thermal insulation layer increases 90 mm, increasing the thickness has no obvious effect on reducing the heat loss. So, it is suggested that the thermal insulation layer thickness should be 75-80mm.

Infrared thermal imaging as a method to study thermogenesis in the neonatal lamb

2014 ◽  
Vol 54 (9) ◽  
pp. 1497 ◽  
Author(s):  
S. A. McCoard ◽  
H. V. Henderson ◽  
F. W. Knol ◽  
S. K. Dowling ◽  
J. R. Webster
Keyword(s):  
Body Temperature ◽  
Heat Loss ◽  
Cold Exposure ◽  
Thermal Imaging ◽  
Core Body Temperature ◽  
Recovery Period ◽  
Exposure Period ◽  
Skin Surface ◽  
Infrared Thermal Imaging ◽  
Core Body

The combination of heat generation and reducing heat loss from the skin surface is important for maintaining core body temperature in a neonate. Thermogenesis studies traditionally focus on measurement of core body temperature but not the contribution of radiated heat loss at the skin surface. This study aimed to evaluate the utility of using thermal imaging to measure radiated heat loss in newborn lambs. Continuous thermal images of newborn lambs were captured for 30 min each during the baseline (11−18°C), cold-exposure (0°C) and recovery (11−18°C) periods by using an infrared camera. Core body temperature measured by rectal thermometer was also recorded at the end of each period. In all, 7 of the 10 lambs evaluated had reduced rectal temperatures (0.4−1°C) between the baseline and recovery periods, while three maintained body temperature despite cold exposure. During the baseline period, infrared heat loss was relatively stable, followed by a rapid decrease of 5°C within 5 min of cold exposure. Heat loss continued to decrease linearly in the cold-exposure period by a further 10°C, but increased rapidly to baseline levels during the recovery period. A temperature change of between 20°C and 35°C was observed during the study, which was likely to be due to changes in vasoconstriction in the skin to conserve heat. The present study has highlighted the sensitivity of infrared thermal imaging to estimate heat loss from the skin in the newborn lamb and shown that rapid changes in heat loss occur in response to cold exposure.

scholarly journals Development of an algorithm for determining the heat transfer coefficient of the body of an isothermal vehicle based on the results of analysis of the heat exchange processes occurring in it

2017 ◽  
Vol 76 (5) ◽  
pp. 306-311 ◽  
Author(s):  
A. A. Golubin ◽  
S. N. Naumenko
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Heat Exchange ◽  
Transfer Coefficient ◽  
Thermal Imaging ◽  
The Body ◽  
Internal Heating ◽  
Heating Method ◽  
Exchange Processes ◽  
The Heat Transfer Coefficient

The article analyzes the heat exchange processes the thermal imaging method using a thermal imaging device. An occurring in the body of an isothermal vehicle when determining algorithm for determining the heat transfer coefficient is proposed, the heat transfer coefficient K by the internal heating method. which makes it possible to calculate its value with an accuracy not The differences are shown in the values of the heat transfer coef-exceeding 5 %, which is regulated by a number of international ficients obtained by the equilibrium internal heating method and normative documents, while reducing the duration of the experiment by at least 6 times. The study gives comparative experimental data and results of calculating the unknown values of K for bodies of isothermal vehicles obtained by the equilibrium method and an express method based on the algorithm described in the article. It is shown that the use of the algorithm for calculating the heat transfer coefficient of the body of an isothermal vehicle will not only increase the productivity of testing stations, but will also lead to the organization of an electronic passport for the thermotechnical state for each body of an isothermal vehicle, the control of which will enable timely diagnosing the thermo-technical condition of the bodies of isothermal vehicles, providing energy-optimal operating modes of energy equipment and, hence, increasing its resource.

Thermal Imaging in Evaluation of the Physical Fitness Level

2017 ◽  
pp. 141-164 ◽  
Author(s):  
Teresa Kasprzyk ◽  
Agata Stanek ◽  
Karolina Sieroń-Stołtny ◽  
Armand Cholewka
Keyword(s):  
Thermal Imaging ◽  
Skin Surface ◽  
The Body ◽  
Body Core Temperature ◽  
Skin Surface Temperature ◽  
Fitness Level ◽  
Surface Temperature Distribution ◽  
Body Core ◽  
Cycle Training ◽  
Basic Level

The thermoregulation mechanisms during the physical effort can be easily study by using the thermovision. The thermoregulation mechanisms in human body keep the body core temperature on basic level 37 ± 2oC. However, the question is if there are any differences in skin surface temperature distribution between trainee sportsmen and amateur. Is there any possibility to show the sportsman level of practise using the thermal imaging? Would it be possible to evaluate the efficiency of athlete or evaluate the level of sports possibilities in average amateur who just wants to start cycle training. To find how the thermoregulation mechanisms work the different measurements were done i.e. during the cyclist endurance test for group of male cyclist (intermediate level of cycling skill) and during the Aerobic Circuit Training (ACT) for trainee and amateur group of women.

Thermal Imaging in Evaluation of the Physical Fitness Level

2021 ◽  
pp. 772-794
Author(s):  
Teresa Kasprzyk ◽  
Agata Stanek ◽  
Karolina Sieroń-Stołtny ◽  
Armand Cholewka
Keyword(s):  
Thermal Imaging ◽  
Skin Surface ◽  
The Body ◽  
Body Core Temperature ◽  
Skin Surface Temperature ◽  
Fitness Level ◽  
Surface Temperature Distribution ◽  
Body Core ◽  
Cycle Training ◽  
Basic Level

The thermoregulation mechanisms during the physical effort can be easily study by using the thermovision. The thermoregulation mechanisms in human body keep the body core temperature on basic level 37 ± 2 oC. However, the question is if there are any differences in skin surface temperature distribution between trainee sportsmen and amateur. Is there any possibility to show the sportsman level of practise using the thermal imaging? Would it be possible to evaluate the efficiency of athlete or evaluate the level of sports possibilities in average amateur who just wants to start cycle training. To find how the thermoregulation mechanisms work the different measurements were done i.e. during the cyclist endurance test for group of male cyclist (intermediate level of cycling skill) and during the Aerobic Circuit Training (ACT) for trainee and amateur group of women.

A preliminary study for the assessment of hypertension using static and dynamic IR thermograms

2018 ◽  
Vol 63 (2) ◽  
pp. 197-206
Author(s):  
Jayanthi Thiruvengadam ◽  
Anburajan Mariamichael
Keyword(s):  
Feature Selection ◽  
Thermal Imaging ◽  
Structural Changes ◽  
Principal Component ◽  
Normal Subjects ◽  
Skin Surface ◽  
The Body ◽  
Preliminary Study ◽  
Average Skin ◽  
Diagnosis Of Hypertension

AbstractStructural changes in blood vessels occur due to prolonged hypertension. Early detection of blood pressure (mm Hg) is essential for disease prevention. The aim of this work is to propose a computer-aided diagnostic (CADx) model for the diagnosis of hypertension using variables derived from non-contact static and dynamic thermal imaging in comparison with the pulse wave velocity (PWV)-derived parameters. Static and dynamic infrared (IR) thermograms of selected skin areas of the body from known hypertensive (n=14) and age- and sex-matched normal subjects were captured. The average skin surface temperature [SST (°C)] of selected skin areas of the body was calculated from a static IR thermogram. After denoising the dynamic IR thermogram using wavelets, the statistical variables power, mean, standard deviation (SD), variance, skewness and kurtosis were calculated. The variables derived from both static and dynamic thermograms were used to develop the CADx model. The performance of the CAD model was also tested by feature selection using principal component analysis (PCA). An accuracy of 75% (sensitivity=78.6%, specificity=71.4%) could be achieved with the average SST (°C) of the static IR thermogram alone. The statistical variables derived from the dynamic IR thermogram alone gave an accuracy of 82% (and 85% after feature selection by PCA), whereas the accuracy using standard methods like variables derived from PWV was only 71.4% (with and without feature selection). The highest accuracy of 89% could be achieved by combining variables like average SST (°C) measured from static and dynamic IR thermograms and PWV-derived variables.

scholarly journals Numerical investigation of heat transfer in a garment convective cooling system

2022 ◽  
Vol 9 (1) ◽  
Author(s):  
Yijie Zhang ◽  
Juhong Jia ◽  
Ziyi Guo
Keyword(s):  
Heat Transfer ◽  
Thermal Comfort ◽  
Cooling System ◽  
Three Dimensional ◽  
Skin Surface ◽  
Air Gap ◽  
The Body ◽  
Three Dimensional Model ◽  
Cooling Air ◽  
Eddy Flow

AbstractA personal microclimate management system is designed to maintain thermal comfort which allows people to overcome a harsh environment. It consists of several micro-fans placed in the garment side seam to provide cooling air. The computational fluid dynamics method was used to simulate the three-dimensional model and analysis the influence of fan’s number and air gap distance. The obtained results depict that the introduced cool airflow will find its way along paths with flow resistance minimized and exhaust through several separated exit. The body heat flux is taken away at the same time. The convection effect is enhanced by the increase in the fans’ numbers, but the fans’ cooling effect varies a lot because of various air gap distances. When the air gap is small enough, the cooling air impact the body surface directly and causes fierce heat loss. While the air gap distance is large enough, the heat transfer along the skin surface could be enhanced by the eddy flow which is existed in the air gap between body and garment. These phenomena can maintain the body’s thermal comfort in a suitable range.

scholarly journals Hidden keys to survival: the type, density, pattern and functional role of emperor penguin body feathers

2015 ◽  
Vol 282 (1817) ◽  
pp. 20152033 ◽  
Author(s):  
Cassondra L. Williams ◽  
Julie C. Hagelin ◽  
Gerald L. Kooyman
Keyword(s):  
Heat Transfer ◽  
Body Temperature ◽  
Sea Ice ◽  
Functional Role ◽  
Emperor Penguin ◽  
Emperor Penguins ◽  
Contour Feather ◽  
Density Pattern ◽  
Transfer Properties

Antarctic penguins survive some of the harshest conditions on the planet. Emperor penguins breed on the sea ice where temperatures drop below −40°C and forage in −1.8°C waters. Their ability to maintain 38°C body temperature in these conditions is due in large part to their feathered coat. Penguins have been reported to have the highest contour feather density of any bird, and both filoplumes and plumules (downy feathers) are reported absent in penguins. In studies modelling the heat transfer properties and the potential biomimetic applications of penguin plumage design, the insulative properties of penguin plumage have been attributed to the single afterfeather attached to contour feathers. This attribution of the afterfeather as the sole insulation component has been repeated in subsequent studies. Our results demonstrate the presence of both plumules and filoplumes in the penguin body plumage. The downy plumules are four times denser than afterfeathers and play a key, previously overlooked role in penguin survival. Our study also does not support the report that emperor penguins have the highest contour feather density.

scholarly journals The Use of Core Warming as a Treatment for Coronavirus Disease 2019 (COVID-19): an Initial Mathematical Model

2020 ◽  
Vol 33 (1) ◽  
pp. 6-15 ◽  
Author(s):  
Marcela Mercado-Montoya ◽  
Nathaniel Bonfanti ◽  
Emily Gundert ◽  
Anne Meredith Drewry ◽  
Roger Bedimo ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Viral Entry ◽  
Therapeutic Option ◽  
Blood Perfusion ◽  
Skin Surface ◽  
The Body ◽  
Hospital Environment ◽  
Body Region ◽  
Temperature Sensitive ◽  
Available Technology

Background: Increasing data suggest that elevated body temperature may be helpful in resolving a variety of diseases, including sepsis, acute respiratory distress syndrome (ARDS), and viral illnesses. SARS-CoV-2, which causes coronavirus disease 2019 (COVID-19), may be more temperature sensitive than other coronaviruses, particularly with respect to the binding affinity of its viral entry via the ACE2 receptor. A mechanical provision of elevated temperature focused in a body region of high viral activity in patients undergoing mechanical ventilation may offer a therapeutic option that avoids arrhythmias seen with some pharmaceutical treatments. We investigated the potential to actively provide core warming to the lungs of patients with a commercially available heat transfer device via mathematical modeling, and examine the influence of blood perfusion on temperature using this approach. Methods: Using the software Comsol Multiphysics, we modeled and simulated heat transfer in the body from an intraesophageal warming device, taking into account the airflow from patient ventilation. The simulation was focused on heat transfer and warming of the lungs and performed on a simplified geometry of an adult human body and airway from the pharynx to the lungs. Results: The simulations were run over a range of values for blood perfusion rate, which was a parameter expected to have high influence in overall heat transfer, since the heat capacity and density remain almost constant. The simulation results show a temperature distribution which agrees with the expected clinical experience, with the skin surface at a lower temperature than the rest of the body due to convective cooling in a typical hospital environment. The highest temperature in this case is the device warming water temperature, and that heat diffuses by conduction to the nearby tissues, including the air flowing in the airways. At the range of blood perfusion investigated, maximum lung temperature ranged from 37.6°C to 38.6°C. Conclusions: The provision of core warming via commercially available technology currently utilized in the intensive care unit, emergency department, and operating room can increase regional temperature of lung tissue and airway passages. This warming may offer an innovative approach to treating infectious diseases from viral illnesses such as COVID-19, while avoiding the arrhythmogenic complications of currently used pharmaceutical treatments.

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