Logic programming and artificial neural networks in breast cancer detection

About 90% of breast cancers do not cause or are capable of producing death if detected at an early stage and treated properly. Indeed, it is still not known a specific cause for the illness. It may be not only a beginning, but also a set of associations that will determine the onset of the disease. Undeniably, there are some factors that seem to be associated with the boosted risk of the malady. Pondering the present study, different breast cancer risk assessment models where considered. It is our intention to develop a hybrid decision support system under a formal framework based on Logic Programming for knowledge representation and reasoning, complemented with an approach to computing centered on Artificial Neural Networks, to evaluate the risk of developing breast cancer and the respective Degree-of-Confidence that one has on such a happening.This work has been supported by FCT – Fundação para a Ciência e Tecnologia within the Project Scope UID/CEC/00319/2013

Moving Lids Direction Effects on MHD Mixed Convection in a Two-Sided Lid-Driven Enclosure Using Nanofluid

Magnetohydrodynamic (MHD) mixed convection flow of Cu–water nanofluid inside a two-sided lid-driven square enclosure with adiabatic horizontal walls and differentially heated sidewalls has been investigated numerically. The effects of moving lids direction, variations of Richardson number, Hartmann number, and volume fraction of nanoparticles on flow and temperature fields have been studied. The obtained results show that for a constant Grashof number (), the rate of heat transfer increases with a decrease in the Richardson and Hartmann numbers. Furthermore, an increase of the volume fraction of nanoparticles may result in enhancement or deterioration of the heat transfer performance depending on the value of the Hartmann and Richardson numbers and the configuration of the moving lids. Also, it is found that in the presence of magnetic field, the nanoparticles have their maximum positive effect when the top lid moves rightward and the bottom one moves leftward

Journal of Solid and Fluid Mechanics An Approximate Model for Slug Flow Heat Transfer in Channels of Arbitrary Cross Section

Abstract In this paper, a novel approximate solution to determine the Nusselt number for thermally developed, slug (lowPrandtl), laminar, single phase flow in channels of arbitrary cross section is presented. Using the Saint-Venant principle in torsion of beams, it is shown that the thermally developed Nusselt number for low-Prandtl flow is only a function of the geometrical parameters of the channel cross section, i.e., area, perimeter and non-dimensional polar moment of inertia. The new proposed model is compared with the existing numerical results for elliptic, rectangular, regular polygonal, flat plate, isosceles triangular, equilateral triangular and circular sector channels. The model predicts the Nusselt number for the above mentioned channels within the about 10% or better with the exception of the circular sector in very small aspect ratios. The new model is expected to be accurate for other singly connected channels and can be used to determine the fully developed turbulent Nusselt number for liquid metal flows. Finally, the proposed model is used to determine the slug flow Nusselt number for unavailable geometries in the literature such as rhombic, circular segment, annular sector channel as well as rectangular channel with semicircular ends

Process Conditions in Preparation of MgCl2 Adduct on Crystalline Structure of the Support in ZN Catalyst

MgCl2/C2H5OH adducts with constant relative ratio of 1/3 were prepared and kept at 120oC for different lengths of times of 5, 10, 20, 30, 50, 90,120 and 220 h. Then the samples were quenched and analyzed by XRD and BET. No meaningful changes were observed in the specific surface area of the samples, while XRD spectra showed 3 peaks at 2θ<15o for samples kept at 120oC for 5 h. These 3 peaks were gradually replaced by a single peak for samples kept at120 oC for 120 h and beyond. Dealcoholation of the samples caused a dramatic change in specific surface area from 3.6 m2/g to 284.7 m2/g. Also XRD indicated that the peak at 2θ <15o totally vanished and it was replaced by a weak amorphous type of peak. Catalysts produced from these supports were used to polymerize ethylene. It was observed that with increasing the specific surface area of the supports and the time of polymerization, the activity of the catalysts was enhanced dramatically

Eulerian-Eulerian two-phase numerical simulation on nanofluid laminar forced convection in a microchannel

In this paper, laminar forced convection heat transfer of a copper–water nanofluid inside an isothermally heated microchannel is studied numerically. An Eulerian two-fluid model is considered to simulate the nanofluid flow inside the microchannel and the governing mass, momentum and energy equations for both phases are solved using the finite volume method. For the first time, the detailed study of the relative velocity and temperature of the phases are presented and it has been observed that the relative velocity and temperature between the phases is very small and negligible and the nanoparticle concentration distribution is uniform. However, the two-phase modeling results show higher heat transfer enhancement in comparison to the homogeneous single-phase model. Also, the heat transfer enhancement increases with increase in Reynolds number and nanoparticle volume concentration as well as with decrease in the nanoparticle diameter, while the pressure drop increases only slightly

Nanoparticle size effect on the convective heat transfer of a nanofluid flow inside a microchannel

This paper aims to study the nanoparticle size effect on the heat transfer enhancement for a copper-water nanofluid flow inside an isothermally heated microchannel using the two-phase approach. To do this, the governing equations for base liquid and nanoparticle phase are solved numerically. The two-phase results show higher heat transfer enhancements in comparison to the homogeneous modeling results. Also, it has been observed that the relative velocity and temperature between the phases is negligible and the nanoparticles distribute in the base liquid evenly. For lower volume concentrations, base liquid contributes more than the nanoparticle in the heat transfer but, for higher volume concentrations, the nanoparticle contribution is dominant. Heat transfer enhancement increases with a decrease in the nanoparticle size. The effect of the nanoparticle size on the heat transfer enhancement is more pronounced for higher volume concentrations