A supervised blood vessel segmentation technique for digital Fundus images using Zernike Moment based features

This paper proposes a new supervised method for blood vessel segmentation using Zernike moment-based shape descriptors. The method implements a pixel wise classification by computing a 11-D feature vector comprising of both statistical (gray-level) features and shape-based (Zernike moment) features. Also the feature set contains optimal coefficients of the Zernike Moments which were derived based on the maximum differentiability between the blood vessel and background pixels. A manually selected training points obtained from the training set of the DRIVE dataset, covering all possible manifestations were used for training the ANN-based binary classifier. The method was evaluated on unknown test samples of DRIVE and STARE databases and returned accuracies of 0.945 and 0.9486 respectively, outperforming other existing supervised learning methods. Further, the segmented outputs were able to cover thinner blood vessels better than previous methods, aiding in early detection of pathologies

Review of phase change emulsions (PCMEs) and their applications in HVAC systems

Phase change material emulsions (PCMEs) are multifunctional fluids consisting of phase change materials (PCMs) and carrier fluids. PCMEs could be potential candidates as heat transfer media in heating, ventilation and air conditioning (HVAC) systems. This is mainly because PCME could take advantage of its high heat capacity to reduce flow rate and thus saving pumping power whilst delivering the same amount of cooling effect. PCME can also simultaneously act as cold storage to shift peak-load to off-peak time and improve the COP of systems. However, the optimum design of integrated system requires a good understanding of flow behaviour and heat transfer characteristics of PCMEs. In this paper, comprehensive reviews of their thermo-physical properties and potential applications as thermal energy storage and as alternative heat transfer fluids in air conditioning systems have been carried out to establish their limitations for future research

Heat transfer of microencapsulated PCM slurry flow in a circular tube

Heat transfer characteristics of microencapsulated phase change material (MPCM) slurry flow in a circular horizontal tube are presented in this paper. Phase change due to the melting is investigated for water-based slurries using microencapsulated 1-bromohexadecane (C16H33Br) with a mass concentrations varying from O to 27.6%. The local heat transfer coefficients varied significantly along the test section when PCM particles were melting. The average Nusselt numbers were calculated based on the local heat transfer data and found to be significantly higher than those for singlephase fluid flow. Two new heat transfer correlations, one used for the slurry under laminar condition (O < Re < 2000) and another used for the slurry under slightly turbulent condition (2200 < Re < 3500), were proposed for predicting the heat transfer behaviors of MPCM slurry in a circular tube.Institute of Textiles and ClothingDepartment of Building Services Engineerin

Methods of heat transfer intensification in PCM thermal storage systems: Review paper

This paper presents a comprehensive review of significant studies that are relevant to thermal energy storage technologies using phase change materials (PCMs). The review focuses on the techniques applied to enhance the performance of thermal storage systems and the methods used to analyse the heat transfer problems in PCMs. In addition, this paper reviews the published results and discussions on the heat transfer intensification methods including application of fins, filling materials, nano-fluids, nano-particles, microencapsulation and the thermal conductivity enhancement method. Furthermore, the experimental and mathematical methods to enhance the thermal conductivity of PCMs are summarised, and the methods used to determine the nanofluid dynamic viscosity in recent investigations are also listed and discussed. The focus of this review is to provide a solid basis for the identification of the optimal design for the various heat transfer applications using PCM