Study Of Various Thermal Conductivity Layers in Bioheat Transfer Against Thermal Distribution on Human Skin with Finite Difference Method (FDM)

Development of science are often found with the connection between science and another that forms a brands new science. one among the new sciences is biomechanics with one among its scientific fields is bioheat transfer which is applied to human skin. one among the factors that influence the heat propagation of skin tissue is thermal conductivity because the ability of materials to conduct heat. the aim of this study was to work out the mathematical model of bioheat transfer with a one-dimensional finite difference method and therefore the effect of thermal conductivity on its temperature distribution. The model is often made with combine the Pennes H.H equation to the steady state then the chosen parameter entered into it. The results of the study were compared between the finite difference method and therefore the analytic method. The results of comparative studies indicate a rise in temperature distribution but between the 2 still have differences (error). Changes in environmental temperature affect the temperature distribution in human skin. While the thermal conductivity of various layers has no significant effect, the worth of temperature distributed between points increases regularly from the core of the body to the outer layer of human ski

High-performance near-infrared imaging for breast cancer detection

We present a method for the noninvasive determination of the size, position, and optical properties of tumors in the human breast. The tumor is first detected by photothermal imaging. It is then sized, located, and optically characterized using designed digital image processing and edge-detection pattern recognition. The method assumes that the tumor is spherical and inhomogeneous and embedded in an otherwise homogeneous tissue. Heat energy is deposited in the tissue by absorption of near-infrared (NIR) Nd:YAG laser radiation, and its subsequent conversion to heat via vibrational relaxation causes a rise in temperature of the tissue. The tumor absorbs and scatters NIR light more strongly than the surrounding healthy tissue. Heat will diffuse through the tissue, causing a rise in temperature of the surrounding tissue. Differentiation between normal and cancerous tissues is determined using IR thermal imaging. Results are presented on a 55-year-old patient with a papillary breast cancer. We found that these results provide the clinician with more detailed information about breast lesions detected by photothermal imaging and thereby enhance its potential for specificity

Solution of hyperbolic bioheat transfer problems by numerical green's functions: the ExGA-linear θ method

This paper presents a time-domain formulation called Explicit Green's approach (ExGA) linear θ method for the solution of the bioheat equation. Starting from the hyperbolic bioheat equation, which includes the parabolic one as a special case, the linear method is incorporated into the standard ExGA time marching scheme. The numerical Green's function is firstly computed in the Laplace transform domain and then back-transformed to the time domain through the Stehfest inversion algorithm. The proposed formulation has the properties of stabilizing the results and suppressing numerical oscillations that appear in the presence of discontinuous solutions as assessed through the analysis of some bioheat transfer problems.

Second law of thermodynamics and urban green infrastructure – A knowledge synthesis to address spatial planning strategies

Planning strategies driven by the second law of thermodynamics (SLT) are innovative approaches to sustainability but they are still in seminal phase. In this article, a coupled review of SLT within spatial planning is accomplished looking at the main applications in urban green infrastructure (UGI) planning. In particular, a systemic review of UGI planning and thermodynamics has been carried out to identify all the occurrences to date in the scientific literature. Secondly, a scoping review of SLT-related concepts of exergy, entropy and urban metabolism is presented in order to investigate the main applications of, and gaps in, urban spatial planning. Results indicate that UGI and ecosystem service planning based on SLT is a relatively new field of research. Moreover, some general indications are derived for the development of spatial UGI planning strategies based on SLT. The work then aims to contribute to the improvement and/or development of even more solid planning strategies supporting a SLTconscious green transition of cities

Convection Due to Spatially Distributed Heating

Convection in an infinite horizontal slot subject to spatially distributed heating has been investigated for a wide range of Prandtl numbers. The primary flow response consists of convection in the form of rolls. When heating wave number alpha is sufficiently large the convection is found to be limited to a layer adjacent to lower wall and a uniform conductive layer emerges at upper section of the slot. Conditions leading to the emergence of secondary convection have been identified using linear stability of the above primary convection. The secondary convection gives rise to longitudinal, or transverse, or oblique rolls; or to oscillatory mode at onset. Three mechanisms of instability have been identified. For small and moderate alpha parametric resonance leads to the pattern of instability that is locked-in with the pattern of heating. The second mechanism is associated with the formation of patterns of vertical temperature gradients and patterns of primary convection currents, operates approximately in the same range of alpha. The third mechanism operates for large alpha where instability is driven by uniform mean vertical temperature gradient created by primary convection and fluid response becoming similar to that found in the case of uniformly heated wall. A rapid stabilization of the oblique rolls is observed when alpha is reduced sufficiently, with the oscillatory mode taking the dominant role. As alpha becomes very small, secondary motions concentrate around the hot spots. When an external flow is introduced into the slot, the heating assists in reduction of the overall drag