Two-dimensional finite element model to study the effect of periodic physical exercise on temperature distribution in peripheral regions of human limbs

2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Babita kumari ◽  
Neeru Adlakha
Keyword(s):  
Finite Element ◽  
Temperature Distribution ◽  
Physical Exercise ◽  
Finite Element Model ◽  
Element Model ◽  
Two Dimensional ◽  
Dimensional Finite Element ◽  
Peripheral Regions

Two-dimensional finite element model to study temperature distribution in peripheral regions of extended spherical human organs involving uniformly perfused tumors

2015 ◽  
Vol 08 (06) ◽  
pp. 1550074 ◽  
Author(s):  
Akshara Makrariya ◽  
Neeru Adlakha
Keyword(s):  
Finite Element ◽  
Temperature Distribution ◽  
Finite Element Model ◽  
Metabolic Activity ◽  
Element Model ◽  
The Body ◽  
Tissue Response ◽  
Two Dimensional ◽  
Human Breast ◽  
Peripheral Regions

Temperature as an indicator of tissue response is widely used in clinical applications. In view of above a problem of temperature distribution in peripheral regions of extended spherical organs of a human body like, human breast involving uniformly perfused tumor is investigated in this paper. The human breast is assumed to be spherical in shape with upper hemisphere projecting out from the trunk of the body and lower hemisphere is considered to be a part of the body core. The outer surface of the breast is assumed to be exposed to the environment from where the heat loss takes place by conduction, convection, radiation and evaporation. The heat transfer from core to the surface takes place by thermal conduction and blood perfusion. Also metabolic activity takes place at different rates in different layers of the breast. An elliptical-shaped tumor is assumed to be present in the dermis region of human breast. A finite element model is developed for a two-dimensional steady state case incorporating the important parameters like blood flow, metabolic activity and thermal conductivity. The triangular ring elements are employed to discretize the region. Appropriate boundary conditions are framed using biophysical conditions. The numerical results are used to study the effect of tumor on temperature distribution in the region.

Three-dimensional finite element model to study temperature distribution in peripheral layers of human limbs immediately after physical exercise

2017 ◽  
Vol 10 (04) ◽  
pp. 1750053 ◽  
Author(s):  
Babita Kumari ◽  
Neeru Adlakha
Keyword(s):  
Finite Element ◽  
Temperature Distribution ◽  
Physical Exercise ◽  
Finite Element Model ◽  
Three Dimensional ◽  
Element Model ◽  
The Body ◽  
Dimensional Finite Element ◽  
Human Limb ◽  
Three Dimensional Finite Element

The physical exercise imposes challenges on the human thermoregulatory system, as heat exchange between the body and environment is substantially impaired, which can lead to decrease in performance and increased risk of heat illness. In view of above a three-dimensional finite element model is proposed to study the effect of different intensities of physical exercise on temperature distribution in peripheral regions of human limbs under moderate climatic conditions. Human limb is assumed to have a cylindrical cross-section. The peripheral region of the human limb is divided into three natural components, namely epidermis, dermis and subdermal tissues. The model incorporates the effect of important physiological parameters like blood mass flow rate, metabolic heat generation, and thermal conductivity of the tissues. Appropriate boundary conditions have been framed based on the physical conditions of the problem. The model is transformed into the discretized variational form and finite element method (FEM) has been employed to obtain the solution. The numerical results have been used to obtain the temperature profiles in the region immediately after exercise for an unsteady state case. The thermal information generated from the model can be useful for developing protocols for improving performance of sportsmen, military persons and labor-intensive workers.

A finite-element model of oxygen diffusion in the pulmonary capillaries

1997 ◽  
Vol 82 (6) ◽  
pp. 2036-2044 ◽  
Author(s):  
Andreas O. Frank ◽  
C. J. Charles Chuong ◽  
Robert L. Johnson
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Oxygen Diffusion ◽  
Flow Characteristics ◽  
Element Model ◽  
Two Dimensional ◽  
Plasma Protein Concentration ◽  
Pulmonary Capillaries ◽  
Dimensional Finite Element ◽  
Barrier Surface

Frank, Andreas O., C. J. Charles Chuong, and Robert L. Johnson. A finite-element model of oxygen diffusion in the pulmonary capillaries. J. Appl. Physiol. 82(6): 2036–2044, 1997.—We determined the overall pulmonary diffusing capacity (Dl) and the diffusing capacities of the alveolar membrane (Dm) and the red blood cell (RBC) segments (De) of the diffusional pathway for O2 by using a two-dimensional finite-element model developed to represent the sheet-flow characteristics of pulmonary capillaries. An axisymmetric model was also considered to assess the effect of geometric configuration. Results showed the membrane segment contributing the major resistance, with the RBC segment resistance increasing as O2 saturation ([Formula: see text]) rises during the RBC transit: RBC contributed 7% of the total resistance at the capillary inlet ([Formula: see text] = 75%) and 30% toward the capillary end ([Formula: see text] = 95%) for a 45% hematocrit (Hct). Both Dm and Dlincreased as the Hct increased but began approaching a plateau near an Hct of 35%, due to competition between RBCs for O2 influx. Both Dm and Dl were found to be relatively insensitive (2∼4%) to changes in plasma protein concentration (28∼45%). Axisymmetric results showed similar trends for all Hct and protein concentrations but consistently overestimated the diffusing capacities (∼2.2 times), primarily because of an exaggerated air-tissue barrier surface area. The two-dimensional model correlated reasonably well with experimental data and can better represent the O2 uptake of the pulmonary capillary bed.

scholarly journals Three-Dimensional Response of the Supported-Deep Excavation System: Case Study of a Large Scale Underground Metro Station

Geosciences ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 76
Author(s):  
Ashraf Hefny ◽  
Mohamed Ezzat Al-Atroush ◽  
Mai Abualkhair ◽  
Mariam Juma Alnuaimi
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Large Scale ◽  
Three Dimensional ◽  
Element Model ◽  
Two Dimensional ◽  
Deep Excavation ◽  
Metro Station ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

The complexities and the economic computational infeasibility associated in some cases, with three-dimensional finite element models, has imposed a motive for many investigators to accept numerical modeling simplification solutions such as assuming two-dimensional (2D) plane strain conditions in simulation of several supported-deep excavation problems, especially for cases with a relatively high aspect ratio in plan dimensions. In this research, a two-dimensional finite element model was established to simulate the behavior of the supporting system of a large-scale deep excavation utilized in the construction of an underground metro station Rod El Farrag project (Egypt). The essential geotechnical engineering properties of soil layers were calculated using results of in-situ and laboratory tests and empirical correlations with SPT-N values. On the other hand, a three-dimensional finite element model was established with the same parameters adopted in the two-dimensional model. Sufficient sensitivity numerical analyses were performed to make the three-dimensional finite element model economically feasible. Results of the two-dimensional model were compared with those obtained from the field measurements and the three-dimensional numerical model. The comparison results showed that 3D high stiffening at the primary walls’ corners and also at the locations of cross walls has a significant effect on both the lateral wall deformations and the neighboring soil vertical settlement.

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