Numerical Prediction of Heat Transfer Patterns in a Subject-Specific Human Upper Airway

2012 ◽  
Vol 134 (3) ◽  
Author(s):  
Prihambodo H. Saksono ◽  
Perumal Nithiarasu ◽  
Igor Sazonov
Keyword(s):  
Heat Transfer ◽  
Body Temperature ◽  
Upper Airway ◽  
Heat Transfer Process ◽  
The Body ◽  
In Vivo Measurement ◽  
Flow And Heat Transfer ◽  
Subject Specific ◽  
Specific Geometry

In this paper, the flow and heat transfer patterns in a subject-specific geometry of the human upper airway is numerically studied. The study was conducted for steady, inspiratory flow associated with quiet normal breathing with a tidal volume of VT = 0.5 L/min and flow rate of Q = 250 cm3/s. The numerical results confirmed in vivo measurement that the majority of heat transfer process takes place inside the nasal cavity. It is apparent that even for extreme cases (T∞ = −30 °C and Twall = 37 °C), the inspired air approached the body temperature by the time it passes the distal nasopharyngeal region. The air temperature reached the body temperature by the time it is in the vicinity of the larynx.

scholarly journals A Computational Study on the Role of Parameters for Identification of Thyroid Nodules by Infrared Images (and Comparison with Real Data)

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4459
Author(s):  
José R. González ◽  
Charbel Damião ◽  
Maira Moran ◽  
Cristina A. Pantaleão ◽  
Rubens A. Cruz ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Thyroid Nodules ◽  
Numerical Study ◽  
Computational Study ◽  
Internal Heat ◽  
Heat Transfer Process ◽  
The Body ◽  
Physical Parameters ◽  
Infrared Sensors ◽  
Wide Range

According to experts and medical literature, healthy thyroids and thyroids containing benign nodules tend to be less inflamed and less active than those with malignant nodules. It seems to be a consensus that malignant nodules have more blood veins and more blood circulation. This may be related to the maintenance of the nodule’s heat at a higher level compared with neighboring tissues. If the internal heat modifies the skin radiation, then it could be detected by infrared sensors. The goal of this work is the investigation of the factors that allow this detection, and the possible relation with any pattern referent to nodule malignancy. We aim to consider a wide range of factors, so a great number of numerical simulations of the heat transfer in the region under analysis, based on the Finite Element method, are performed to study the influence of each nodule and patient characteristics on the infrared sensor acquisition. To do so, the protocol for infrared thyroid examination used in our university’s hospital is simulated in the numerical study. This protocol presents two phases. In the first one, the body under observation is in steady state. In the second one, it is submitted to thermal stress (transient state). Both are simulated in order to verify if it is possible (by infrared sensors) to identify different behavior referent to malignant nodules. Moreover, when the simulation indicates possible important aspects, patients with and without similar characteristics are examined to confirm such influences. The results show that the tissues between skin and thyroid, as well as the nodule size, have an influence on superficial temperatures. Other thermal parameters of thyroid nodules show little influence on surface infrared emissions, for instance, those related to the vascularization of the nodule. All details of the physical parameters used in the simulations, characteristics of the real nodules and thermal examinations are publicly available, allowing these simulations to be compared with other types of heat transfer solutions and infrared examination protocols. Among the main contributions of this work, we highlight the simulation of the possible range of parameters, and definition of the simulation approach for mapping the used infrared protocol, promoting the investigation of a possible relation between the heat transfer process and the data obtained by infrared acquisitions.

In vivo measurement of lithium in the body by a neutron activation analysis technique

1986 ◽  
Vol 13 (1) ◽  
pp. 45-49 ◽  
Author(s):  
D. Glaros ◽  
A. F. LoMonte ◽  
K. J. Ellis ◽  
S. Yasumura ◽  
R. W. Stoenner ◽  
...  
Keyword(s):  
Neutron Activation Analysis ◽  
Activation Analysis ◽  
Neutron Activation ◽  
The Body ◽  
In Vivo Measurement ◽  
Analysis Technique

scholarly journals PRE AND POSTPRANDIAL THERMOGRAPHIC PROFILE OF GREEN IGUANAS (IGUANA IGUANA)

2016 ◽  
Vol 73 (2) ◽  
pp. 425
Author(s):  
Simona Rusu ◽  
Zdenek Knotek ◽  
Radu Lacatus ◽  
Ionel Papuc
Keyword(s):  
Heat Transfer ◽  
Body Temperature ◽  
Temperature Difference ◽  
The Body ◽  
Significant Difference ◽  
Before And After ◽  
Significant Temperature ◽  
Green Iguanas ◽  
The Right ◽  
Head Temperature

Abstract The body temperature of 10 clinically healthy green iguanas (Iguana iguana) was measured using a thermographic camera (FLIR E6, Flir Systems Sweden) before and after the food was offered. For each animal there were performed a total of 6 measurements (3 before feeding and 3 after the food was offered). The purpose of this experiment was to observe the thermographic pattern of the body before and after the feeding, since herbivore reptiles tend to bask after the feeding to increase the body temperature that will help them afterwards digest the food. The animals were housed in individual vivariums with every animal having a basking spot available. The pictures were taken outside the vivarium in an adjacent room. The animals were handled with gloves and transported in a cardboard box in order to avoid heat transfer between the handler and the iguana that would have produced thermal artefacts. Each individual was placed on a table on a styrofoam slate, again, to avoid the heat transfer between the table and the animal`s body. For each animal a total of 4 pictures were taken (up, front, left and right). The pictures were analysed with the FLIR Tools program that is provided by the manufacturer and 3 temperatures were taken into consideration (the head temperature, body temperature on the right side and body temperature on the left side). The temperatures were compared between them and with the temperature of the vivariums that consisted of the average between the temperature in 3 different spots (basking spot, the feeding bowl site and the coldest spot) measured with an infrared thermometer GM300 (Benetech, China). The temperature of the body was dependent on the vivarium temperature and it was a significant temperature difference between the measurements before the feeding and after the feeding. Also we discovered a significant difference between the head temperature and the body temperature on the left side before the feeding that disappeared after the animals ate. There was also a significant difference between the temperature on right side and on left side of the animals both before and after the feeding. No significant temperature difference was observed between the head and the right side of the body neither before nor after the feeding.

Direct Determination of the Body Content of Radionuclides: Abstract

2003 ◽  
Vol 3 (1) ◽  
pp. 9-9
Author(s):  
R. Griffith ◽  
H. Bergmann ◽  
F. A. Fry ◽  
D. Hickman ◽  
J.-L. Genicot ◽  
...  
Keyword(s):  
Direct Measurement ◽  
Direct Determination ◽  
The Body ◽  
Whole Body ◽  
Control Measurement ◽  
In Vivo Measurement ◽  
Calibration Methods ◽  
Partial Body ◽  
And Control

Previous ICRU reports have dealt with the formulation and properties of tissue substitutes and phantoms that are used to calibrate in vivo measurement systems. This report provides guidance on the overall process of the direct measurement of radionuclides in the human body for radiation protection and medical applications. It addresses the detectors and electronics used for the measurement; methods of background reduction and control; measurement geometries for whole body, partial body or organ counting; physical and mathematical calibration methods; data analysis; and quality assurance. It is directed to readers who need practical advice on the establishment and operation of direct measurement facilities.

scholarly journals Two-layer nanofluid flow and heat transfer in a horizontal microchannel with electric double layer effects and magnetic field

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Qingkai Zhao ◽  
Hang Xu ◽  
Longbin Tao
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Double Layer ◽  
Electric Double Layer ◽  
Lower Layer ◽  
Fluid Velocity ◽  
Heat Transfer Process ◽  
The Body ◽  
Nanofluid Flow ◽  
Content Type

Purpose The purpose of this paper is to investigate the immiscible two-layer heat fluid flows in the presence of the electric double layer (EDL) and magnetic field. The effects of EDL, magnetic field and the viscous dissipative term on fluid velocity and temperature, as well as the important physical quantities, are examined and discussed. Design/methodology/approach The upper and lower regions in a horizontal microchannel with one layer being filled with a nanofluid and the other with a viscous Newtonian fluid. The nanofluid flow in the lower layer is described by the Buongiorno’s nanofluid model with passively controlled model at the boundaries. An appropriate set of non-dimensional quantities are used to simplify the nonlinear systems. The resulting coupled nonlinear equations are solved by using homotopy analysis method. Findings The present work demonstrates that increasing the EDL thickness and Hartmann number can restrain the fluid flow. The Brinkmann number has a significant role in the enhancement of heat transfer. It is also identified that the influence of EDL effects on microflow cannot be ignored. Originality/value The effects of viscous dissipation involved in the heat transfer process and the body force because of the EDL and the magnetic field are considered in the thermal energy and momentum equations for both regions. The detailed derivation procedure of the analytical solution for electrostatic potential is provided. The analytical solutions can lead to improved understanding of the complex microfluidic systems.

Finite Element Thermal Analysis on Heat Transfer Performance of Rectangular Micro – Groove Flat Heat Pipe

2013 ◽  
Vol 721 ◽  
pp. 456-460
Author(s):  
Yi Bing Liu
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Thermal Analysis ◽  
Heat Pipe ◽  
Heat Transfer Process ◽  
Pipe Surface ◽  
Iterative Computation ◽  
Flow And Heat Transfer ◽  
The Mathematical Model ◽  
Flat Heat Pipe

Having fully considered the influence of gas-liquid interfacial friction on the heat transfer characteristics of heat pipe within the channel, the mathematical model of the flow and heat transfer process in the Rectangular Micro-groove flat heat pipe is established. The simulation is performed by using thermal analysis software ANSYS. The iterative computation values of the center point temperature of the heat pipe surface being compared with the simulation results, the error is only 5.27% and the two are basically the same values, which shows that the mathematical model has a guiding significance on the analysis of heat pipe theory.

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