Smoothed particle hydrodynamics for blood flow analysis: development of particle lifecycle algorithm

The aim of this research was to facilitate the application of Smoothed Particle Hydrodynamics (SPH) method to Computational Fluid Dynamics analysis of turbulent flow through complex geometry blood vessels, and to compare it with the state-of-the-art Finite Element Method (FEM). SPH offers the possibility to observe motion of fluid fragment or particle inclusion within the Lagrangian material framework, giving researchers greater insight into the Fluid-Structure interaction such as transportation and distribution of medical particles, or buildup of plaque in atherosclerosis. In order to generate the fluid flow in SPH, the particles are created at inlet, and destroyed at the outlet. In this paper we present a novel lifecycle algorithm for generation and destruction of the particles using particle types, which is more flexible and suitable for the complex geometry models in comparison to the current state of the art commercial solutions, which use boundary planes. Our algorithm features mother and new-born particle types located at inlets used for the particle flow generation, and at the outlets, we have dying and killer particle types, which are used for deletion of particles. Based upon the current neighbors, the type of the particle is updated within the nearest neighbor search method, which is invoked in each time step. The capabilities of the new algorithm are demonstrated using a benchmark example and a realistic patient specific geometry, showing similar results, but the SPH advantages of particle tracking are yet to be utilized in our future work.Ministry of Education, Science and Technological Development of the Republic of SerbiaPublishe

PREVENTION OF ADENOVIRAL EYE INFECTION - REVIEW

Epidemic viral conjunctivitis caused by adenovirus is the most common infectious conjunctivitis. The exact incidence of adenoviral conjunctivitis is still poorly known, but there are two well-defined adenoviral keratoconjunctivitis clinical syndromes: epidemic keratoconjunctivitis (EKC) and pharyngoconjunctival fever (PCF). Epidemic keratoconjunctivitis is also the most severe form and presents with watery discharge, hyperemia, chemosis and ipsilateral lymphadenopathy. Diagnosis is mainly clinical, but its etiology can be confirmed using cell cultures, antigen detection, polymerase chain reaction or immune-chromatography. Multiple treatments have been tried for this disease, but none of them seem to be completely effective. Viruses are resistant to desiccation and certain common surface disinfectants. Prevention is the most reliable and recommended strategy to control this epidemic infection. Global epidemic surveillance system definitely needs to be established to monitor and analyze the epidemic conjunctivitis in the future. There is clearly a need for the national and the military public health institutions to work together on guidelines to handle future challenges

Dealing with the effect of air in fluid structure interaction by coupled SPH-FEM methods

© 2019 by the authors. Smoothed particle hydrodynamics (SPH) and the finite element method (FEM) are often combined with the scope to model the interaction between structures and the surrounding fluids (FSI). There is the case, for instance, of aircrafts crashing on water or speedboats slamming into waves. Due to the high computational complexity, the influence of air is often neglected, limiting the analysis to the interaction between structure and water. On the contrary, this work aims to specifically investigate the effect of air when merged inside the fluid-structure interaction (FSI) computational models. Measures from experiments were used as a basis to validate estimations comparing results from models that include or exclude the presence of air. Outcomes generally showed a great correlation between simulation and experiments, with marginal differences in terms of accelerations, especially during the first phase of impact and considering the presence of air in the model

Dealing with the Effect of Air in Fluid Structure Interaction by Coupled SPH-FEM Methods

Smoothed particle hydrodynamics (SPH) and the finite element method (FEM) are often combined with the scope to model the interaction between structures and the surrounding fluids (FSI). There is the case, for instance, of aircrafts crashing on water or speedboats slamming into waves. Due to the high computational complexity, the influence of air is often neglected, limiting the analysis to the interaction between structure and water. On the contrary, this work aims to specifically investigate the effect of air when merged inside the fluid–structure interaction (FSI) computational models. Measures from experiments were used as a basis to validate estimations comparing results from models that include or exclude the presence of air. Outcomes generally showed a great correlation between simulation and experiments, with marginal differences in terms of accelerations, especially during the first phase of impact and considering the presence of air in the model

Analysis of three-dimensional interface corner cracks

© 2019, Faculty of Mechanical Engineering, Belgrade. The growth of an interfacial crack, from the straight corner along the joint plane between the two long plates made of different materials is considered in this paper. Three different shapes of the crack front are analyzed: the concave, triangular and the quarter circular shape. Results are presented for variations of the normalized stress intensity factors of all the three crack loading Modes, As well as the normalized phase angles and the normalized energy release rate, all in terms of an angle, which measures the distance from the symmetry plane

Numerical study of the effect of dental implant inclination

© 2017, Journal of the Serbian Society for Computational Mechanics. This paper contains the results of a research focused on the determination of the influence of an implant inclination on the strain state throughout the acrylic block with implant. The aim of the presented research is to qualitatively determine the regions with the greatest strain fields on the models. The finite element models of implant and acrylic block are developed for predefined implant inclinations in order to analyze the influence of implant inclination on deformations on the outer surface of acrylic block. The comparative contour plots of stress and strain state of analyzed models, as well as the comparative diagrams with obtained results, are presented. The conclusions about the inclination angle which leads to the higher strains in the block-implant are explained. Obtained results could be applied for the planning of future experimental studies which could utilize this and similar models to determine their load transfer characteristics, and could be included in the planning of dental implant position, and prediction of successful dental therapy

BLIND SERBIAN RULERS AND FAMOUS PERSONS

History and medicine were an integral part of life-being of blind serbian acters. One of the main actors was half-blind serbian ruler, Stefan of Decani and whose name was associated with first ophthalmologic hospital and precursor of the eye`s injuries care. After, national reputation as Stefan Blind Righteous, ruler of the Serbian despot between 1458. and 1459. (member of Brankovic`s dinasty), and he was blinded by eye injuries burns. The famous national was also Filip Visnjic, as blind minstrel and authentic creator of serbian folk traditions, with sequels as a child, by bilateral infective panuveitis

PREVENTION OF ADENOVIRAL EYE INFECTION - REVIEW

Epidemic viral conjunctivitis caused by adenovirus is the most common infectious conjunctivitis. The exact incidence of adenoviral conjunctivitis is still poorly known, but there are two well-defined adenoviral keratoconjunctivitis clinical syndromes: epidemic keratoconjunctivitis (EKC) and pharyngoconjunctival fever (PCF). Epidemic keratoconjunctivitis is also the most severe form and presents with watery discharge, hyperemia, chemosis and ipsilateral lymphadenopathy. Diagnosis is mainly clinical, but its etiology can be confirmed using cell cultures, antigen detection, polymerase chain reaction or immune-chromatography. Multiple treatments have been tried for this disease, but none of them seem to be completely effective. Viruses are resistant to desiccation and certain common surface disinfectants. Prevention is the most reliable and recommended strategy to control this epidemic infection. Global epidemic surveillance system definitely needs to be established to monitor and analyze the epidemic conjunctivitis in the future. There is clearly a need for the national and the military public health institutions to work together on guidelines to handle future challenges