The report is aimed at formulating and validating the computational model for the isothermal twophase flow with free-surfaces incorporating porous medium. The flow configuration consists of the liquid droplet impacting on and simultaneously spreading over and within a porous substrate. The interface capturing methodology implemented in the open-source software OpenFOAM based on the volume-of-fluid (VOF) model in the framework of Computational Fluid Dynamics (CFD) is extended to incorporate the flow within the porous medium. The potential of the model is evaluated by contrasting the results of numerical simulations to the existing experimental results.

Abstract Objective: The aim of the study was to determine the total concentration of fatty acids (FAs) in the maternal vein serum and in the umbilical vein serum in pregnant women suffering from Type 1 diabetes compared to healthy women. Additional goal was to determine the percentages of arachidonic (AA) and docosahexaenoic acid (DHA) in comparison to the total concentration of FAs. Methods: The study included 63 pregnant women, 32 suffering from Type 1 diabetes and 31 healthy pregnant women. Extraction of total lipids was performed using gas chromatography. Results: There was statistically significant difference in the total FAs concentration in the maternal vein serum and the umbilical vein serum between the two groups. There was a statistically significant higher concentration of total FAs in the maternal and umbilical vein serum of the diabetic group. Higher AA and DHA concentrations were found in the maternal vein serum compared to an umbilical vein serum of the diabetic group. Conclusion: No difference was found in AA and DHA percentages in the maternal or in the umbilical vein serum of diabetic pregnant women. Despite of T1DM, a good metabolic control leads to insignificant changes in the AA and DHA levels in diabetic pregnancy.

CILJ: Cilj istraživanja je bio odrediti ukupnu koncentraciju slobodnih masnih kiselina u serumu majcine krvi i u serumu umbilikalne vene trudnica koje boluju od secerne bolesti tipa 1 u usporedbi sa zdravim trudnicama. Dodatni cilj je bio odrediti i analizirati koncentraciju (mg/L) omega- 3 masnih kiselina (ALA, EPA, DHA) u usporedbi sa ukupnom koncentracijom slobodnih masnih kiselina u serumu majcine krvi i u serumu umbilikalne vene trudnica koje boluju od secerne bolesti tipa 1 u usporedbi sa zdravim trudnicama. METODE: U istraživanje je bilo ukljuceno 63 trudnice, 32 koje boluju od secerne bolesti tipa 1 te 31 zdrava trudnica. Ekstrakcija slobodnih masnih kiselina je izvedena metodom plinske kromatografije. REZULTATI: Postoji statisticki znacajna razlika u koncentraciji ukupnih masnih kiselina u serumu majcine krvi i u serumu umbilikalne vene između dvije skupine.Također postoji statisticki znacajna povecana koncentracija slobodnih masnih kiselina u serumu majcine krvi i umbilikalne vene trudnica sa secernom bolesti tipa 1. Nađene su povecane koncentracije ALA, EPA and DHA masnih kiselina u serumu majcine krvi u usporedbi sa serumom umbilikalne vene u trudnica sa secernom bolesti tipa 1. ZAKLJUCAK: Nase istraživanje je pokazalo statisticku razliku u koncentraciji DHA masne kiseline u serumu majcine krvi i umbilikalne vene trudnica sa secernom bolesti tipa 1 u usporedbi sa zdravim trudnicama.

This work is devoted to investigation of free-surface flow associated with drop impact. The main goal of the work is the computational and the theoretical study of the flow generated by drop collisions and drop impact onto different surfaces, with relevance for spray impingement. The considered flow configurations include drop impact onto a shallow liquid layer, binary drop collision, drop impact onto a dry wall, nonisothermal drop impact onto a heated wall with the accompanying simultaneous heat transfer within the wall, and drop impact onto a porous substrate. The potential of the new interface capturing methodology developed by OpenCFD Ltd and based on the volume-of-fluid (VOF) model within the framework of Computational Fluid Dynamics (CFD) is evaluated by contrasting the results of numerical simulations to the in-house experimental results and the existing experimental and numerical result databases. The novelty in the numerical approach is the introduction of an additional convective term into the equation for the indicator function, which acts as an artificial compressive contribution in the integrated equation and enables suppression of the numerical diffusion thereby providing a sharp definition of free surfaces. The flows studied are treated as being laminar and computed in the framework of the finite-volume numerical method. In general, the numerical model and the computational procedure demonstrate good predictive capabilities by reproducing correctly the studied flows mentioned above, both qualitatively and quantitatively. All important effects observed in the experiments are reproduced and particularly some distinctive features of the flow are properly captured. The numerical simulations of the different flow configurations pertinent to spray impact provide a detailed insight into the dynamics of the flow and enable analytical modeling using simplified theoretical approaches. In particular the computational results provide all the flow details which are inaccessible by present experimental techniques, they are used to prove the theoretical assumptions and yield the required database for defining new flow patterns and their analytical modeling.

This study is devoted to the analysis of inertia dominated axisymmetric drop collisions with a dry substrate or with another liquid drop. All the previous theoretical and semiempirical models of drop collisions are based on the assumption that the flow in the lamella and its thickness are determined by the impact conditions, mainly by the Reynolds and Weber numbers. In this study the existing experimental data are compared to existing and new numerical simulations for the shape of the lamella generated at the early times of drop impact for various impact conditions. The results show that if the Reynolds and Weber numbers are high enough, the evolution of the lamella thickness almost does not depend on the viscosity and surface tension. Therefore these results completely change our understanding of the flow generated by drop collisions. Moreover, we demonstrate that the theoretical models based on the approximation of the shape of the deforming drop by a disk and the models based on the energy balance appr...

In the present work experimental, numerical, and theoretical investigations of a normal drop impact onto a liquid film of finite thickness are presented. The dynamics of drop impact on liquid surfaces, the shape of the cavity, the formation and propagation of a capillary wave in the crater, and the residual film thickness on the rigid wall are determined and analyzed. The shape of the crater within the film and the uprising liquid sheet formed upon the impact are observed using a high-speed video system. The effects of various influencing parameters such as drop impact velocity, liquid film thickness and physical properties of the liquids, including viscosity and surface tension, on the time evolution of the crater formation are investigated. Complementary to experiments the direct numerical simulations of the phenomena are performed using an advanced free-surface capturing model based on a two-fluid formulation of the classical volume-of-fluid (VOF) model in the framework of the finite volume numerical method. In this model an additional convective term is introduced into the transport equation for phase fraction, contributing decisively to a sharper interface resolution. Furthermore, an analytical model for the penetration depth of the crater is developed accounting for the liquid inertia, viscosity, gravity, and surface tension. The model agrees well with the experiments at the early times of penetration far from the wall if the impact velocity is high. Finally, a scaling analysis of the residual film thickness on the wall is conducted demonstrating a good agreement with the numerical predictions.

Objective: to determine epidemiological characteristics, i.e. the occurrence of respiratory syncytial virus (RSV) infection in Croatian children with acute respiratory tract infections. Methods: At Virology Department, Croatian National Institute of Public Health (CNIPH), we tested nasopharyngeal secretions obtained from 1232 patients most of whom were hospitalized in two Zagreb hospitals for acute respiratory infections. Demonstration of the virus was by isolating it in cell culture and/or by detecting it with monoclonal antibodies in the direct immunofluorescence assay. Resultats: Most often, the virus demonstrated was RSV (43.8% ; 540/1232). Other respiratory viruses (adeno, parainfluenza, influeza) were shown considerably less commonly (5.1%). Viral infection could not be demonstrated in 629 (51.1%) patients. As to bronchiolitis, RSV was demonstrated to be its most common cause (60.77% ; 251/412). It was also proven to be the most common causative agent of infections in children aged 0-6 months (55.6% ; 300/540). Bronchiolitis (63% ; 190/300) and, less commonly, pneumonia (9.7% ; 29/300) were the diagnoses linked with RSV in this age group. On the other hand, RSV was demonstrated in 21%(63/300) of the children diagnosed with upper respiratory tract infection (URTI). We showed the presence of the majority of RSV infections in winter months, i.e. between November and June. Conclusion:RSV is a common cause of lower respiratory tract infections in Croatian infants and young children with its annual outbreaks occurring in winter season. Their onset is mostly in November.

Respiratorni sincicijski virus (RSV) cesti je uzrocnik akutnih disnih infekcija u dojencadi i male djece. Najteže klinicke manifestacije, u vidu bronhiolitisa opisuju se u djece do 6 mjeseci života. U razdoblju od 1. travnja 1994. do 31. ožujka 1999. godine u Odjelu za virologiju Hrvatskog zavoda za javno zdravstvo obrađeni su nazofaringealni sekreti 1232 bolesnika, koji su hospitalizirani uglavnom u dvije zagrebacke bolnice zbog akutne respiratorne infekcije. Dokaz virusa ucinjen je izolacijom u stanicnoj kulturi i/ili detekcijom virusa pomocu monoklonskih protutijela u izravnom imunofluorescentnom testu. RSV bio je nacesce dokazan virus (43, 8 % ; 540/1232). Ostali respiratorni virusi (adeno, parainfluenca, influenca) dokazani su znatno rjeđe (5, 1 %). U 629 (51, 1 %) bolesnika nije dokazana virusna infekcija. RSV dokazan je kao najcesci uzrocnik bronhiolitisa (60, 77% ; 251/413). Također je dokazan kao najcesci uzrocnik infekcija u djece od 0-6 mjeseci života (55, 6% ; 300/540). U ovoj dobnoj skupini najcesca dijagnoza povezana sa RSV bio je bronhiolitis (63% ; 190/300) rjeđe pneumonija (9, 7% ; 29/300), dok je u djece s dijagnozom infekcije gornjeg dijela disnog sustava dokazan u 21% (63/300). Najveci broj RSV infekcija dokazan je u zimskim mjesecima tj. od studenog do lipnja.