Efficient solution of 3D electromagnetic eddy-current problems within the finite volume framework of OpenFOAM

Eddy-current problems occur in a wide range of industrial and metallurgical applications where conducting material is processed inductively. Motivated by realising coupled multi-physics simulations, we present a new method for the solution of such problems in the finite volume framework of foam-extend, an extended version of the very popular OpenFOAM software. The numerical procedure involves a semi-coupled multi-mesh approach to solve Maxwell's equations for non-magnetic materials by means of the Coulomb gauged magnetic vector potential and the electric scalar potential. The concept is further extended on the basis of the impressed and reduced magnetic vector potential and its usage in accordance with Biot-Savart's law to achieve a very efficient overall modelling even for complex three-dimensional geometries. Moreover, we present a special discretisation scheme to account for possible discontinuities in the electrical conductivity. To complement our numerical method, an extensive validation is completing the paper, which provides insight into the behaviour and the potential of our approach.Comment: 47 pages, improved figures, updated references, fixed typos, reverse phase shift, consistent use of inner produc

Primjena Naval Hydro Paketa za Dvofazna Strujanja

Ovaj rad prikazuje pregled primjene NavalHydro paketa u programu OpenFOAM za simulacije viskoznih, turbulentnih, dvofaznih strujanja sa slobodnom površinom. Za praćenje slobodne površine se koristi "Volume of Fluid" metoda, te se numerički proračuni vrše metodom kontrolnih volumena. Programski paket NavalHydro omogućava različite vrsta simulacija vezane za brodsku hidrodinamiku, kao i za ostala područja gdje postoje dominantna strujanja sa slobodnom površinom. U ovom radu su ukratko prikazani primjeri otpora broda na mirnom moru, kao i gibanje broda kao krutog tijela na valovima. Također je prikazana simulacija kolapsa brane u kojoj vodeni val udara nepomičan, kruti stup

OpenFOAM u brodskoj hidrodinamici

Tema ovog rada je primjena programskog paketa OpenFOAM u brodskoj hidrodinamici. Matematički model dvofaznog strujanja sa slobodnom površinom uz korištenje "Volume of Fluid" metode je ukratko prikazan. Za diskretizaciju jednadžbi se koristi metoda kontrolnih volumena. Rezultati otpora broda na mirnom moru uspoređeni su s eksperimentalnim podatcima za dvije brodske forme. Prikazane su i simulacije vezane za pomorstvenost plovnih objekata. Razvijeni programski paket podržava pomične mreže, te se može koristiti za simulacije sa nametnutim harmonijskim gibanjem pojedinog stupnja slobode. Kao primjer, prikazani su rezultati harmonijskog zanošenja broda pri konstantoj brzini napredovanja. Konačno je prikazana simulacija poniranja i posrtanja broda koji napreduje konstantnom brzinom u polju nailaznih valova

Qualitative Analysis of Antimony, Bismuth and Arsenic in Mixtures

Cations of antimony, bismuth and arsenic react with potassium iodide and ether in presence of hydrochloric acid. The liquid reaction products can be hydrolysed and the three metal ions will accumulate in the third liquid phase which will form from the originally two phase system (ether-water). The next step is to determine whether the obtained product consists of an individual liquid compound only or it is a binary or ternary mixture of the liquid compounds of the three cations in question

Mental health of refugees, asylum seekers and migrants: An overview of challenges and good practice examples

U poslednjih nekoliko godina, broj izbeglica, migranata i tražilaca azila dramatično je porastao širom sveta. Srbija, kao glavna tranzitna zemlja, trenutno je domaćin za preko 6,000 novih tražilaca azila i izbeglica, za preko 26,200 izbeglica i 198,500 interno raseljenih lica iz regiona bivše Jugoslavije, kao i za 1,950 osoba pod rizikom od gubitka države. Migranti su često pod akutnim i hroničnim stresom. Mnogi od njih traumatizovani su u svojim domovinama i tokom puta, usled progona, nasilja, povreda ljudskim prava, i suočeni su sa stalnim stresorima u zemljama egzila. Obimna istraživanja pokazala su povećane stope i znatnu varijabilnost u prevalenciji kratkoročnih i dugoročnih problema mentalnog zdravlja među izbeglicama, tražiocima azila i migrantima. Najprevalentniji psihijatrijski poremećaji su depresija, anksioznost, prolongirano tugovanje, somatoformni poremećaji, psihoze, zloupotreba supstanci, kao i poremećaji specifično povezani sa stresom, posebno posttraumatski stresni poremećaj. Hitno je potrebno ponuditi sistematične i održive solucije za zaštitu mentalnog zdravlja, kako bi se smanjili sa traumom povezani problemi mentalnog zdravlja i prevenirale dogoročne posledice. Multisektorni, na dokazima zasnovan, multidisciplinarni pristup, prepoznat je kao krucijalni u prepoznavanju potreba ovih populacija i omogućavanju adekvatne zaštite njihovog mentalnog zdravlja i psihosocijalnog blagostanja.In the past few years the number of refugees, migrants and asylum seekers worldwide has increased dramatically. Serbia, as a mainly transit country currently hosts over 6,000 new asylum-seekers and refugees, over 26.200 refugees and 198.500 internally displaced persons from the ex-Yugoslavia region, and 1.950 persons at risk of statelessness. Migrants are often under acute and chronic stress. Many of them were traumatized in their homelands and during their journey , due to persecution, violence, and human right violations, and they are confronted with ongoing stressors in the exile countries. Extensive research has shown increased rates and substantial variability in the prevalence of short-term and long-term mental health problems among refugees, asylum seekers and migrants. The most prevalent psychiatric disorders are depression, anxiety, prolonged grief, somatoform disorders, psychosis, substance use disorders, and disorders specifically related to stress, particularly posttraumatic stress disorder. It's urgent to offer a systemic and sustainable solutions for mental health protection, in order to reduce trauma related mental health problems and prevent long-term consequences. Multisectoral, evidence-based and multidisciplinary approach is recognized as crucial in identifying needs of these populations and enabling proper protection of their mental health and psychosocial wellbeing