MUSLIMS IN THE PRACTICE OF THE EUROPEAN COURT OF HUMAN RIGHTS THROUGH THE PRISM OF FREEDOM OF RELIGION IN EDUCATION

In this paper, the authors presented the characteristic cases from the case law of theEuropean Court of Human Rights in which members of the Islamic community consideredthat their freedom of religion under Article 9 of the European Convention on Human Rightsand Fundamental Freedoms has been violated. At the same time, in those cases, there wasfrequently violation of Article 2 of Protocol No. 1 to the Convention, which provides for theright to education, cumulatively with above mention article. The starting point is the case ofDahlab v. Switzerland, after which the authors specifically addressed several other cases inwhich the European Court of Human Rights considered these rights

Estimation of rotary equipment integrity using fracture mechanics parameters

Integritet konstrukcija kao naučna i inženjerska disciplina kao deo mehanike loma obuhvata analizu stanja i dijagnostiku ponašanja i otkaza, procenu veka i revitalizaciju konstrukcija, kao što je poznato od ranije. Primenom metoda definisanih ovom naučnom disciplinom mogu se odrediti „slaba“ mesta u konstrukciji, pre nastanka prsline kao i u prisustvu prsline kod konstrukcija koje su izložene razlitičitim tipovima opterećenja. Procena integriteta rotacione opreme, kao što je vratilo turbine, predstavlja poseban izazov zbog prirode njegovog opterećenja. Kada se na u ceo problem doda i uticaj prsline problem postaje još složeniji i zahteva uključivanje više naučnih disciplina i alata, poput softverskih paketa kojima je moguće simulirati radne uslove opreme, tačnije, dinimačko opterećenje koje može izazvati zamor materijala. Tema ove doktorske disertacije je istraživanje ponašanja rotacione opreme, konkretno vratila turbine, Hidroelektrane „Đerdap II“ u prisustvu prslina sa ciljem određivanja integriteta i preostalog radnog veka vratila turbine. Opasnost u slučaju prisustvu prsline kod ovog tipa opreme je mogućnost pojave krtog loma koji je, po prirodi, nepredvidiv i često sa fatalnim posledicama. Posebna pažnja u ovoj studiji posvećena je mestima koja izazivaju koncentraciju napona. U rešavanju problema procene integriteta rotacione opreme vratila hidroelektrane korišćeni su softverski paketi Abaqus i MORFEO, odnosno principi proširene metode konačnih elemenata (eng. XFEM). Kao ulazni podaci u primeni XFEM metode primenom ovih paketa korišćeni si eksperimentalni rezultati primenom koncepta elasto-plastične mehanike loma kao i primena poznatog Parisovog zakona sa ciljem određivanja brzine rasta zamorne prsline. Dobijeni podaci eksperimentalnim ispitivanjima, konkretno vrednosti parametara C i m poznatog Parisovog zakona, poslužili su kao osnova za urađene numeričke simulacije rasta zamorne prsline u samom vratilu trubine primenom zakona linealno-elastične mehanike loma. Pored toga, u ovoj studiji urađena je naponska analiza vratila turbine kao i neposredno poređenje analitičkih i numeričkih rezultata. Osnovni cilj celokupne studije može se svesti na objašnjenje kompleksnog stanja i generalno ponašanje rotacione opreme, odnosno vratila turbine u prisustvu prslina nastalih zamornim opterećenjem i u prisustvu koncetratora napona. Može se istaći da je i akcenat ove studije utvrđivanje zavisnosti brzine rasta prsline od veličine prsline za određenu geometriju vratila na osnovu čije je moguće proceniti integritet i vek vratila, pored svih poznatih osobina materijala. Indirektno, razvijeni i predstavljeni numerički modeli u ovoj disertaciji, kao i eksperimentalne procedure koji imaju veliku primenljivost u oblasti procene integriteta generalno kod opreme ovog tipa takođe su imali za cilj davanje naučnom ivi inženjerskom doprinosu analize ove studije sa ciljem utvrđivanja integriteta i preostalog radnog veka opreme izložene zamarajućem opterećenju u prisustvu prsline.As it is known, structural integrity as a scientific and engineering discipline as part of fracture mechanics includes structure analysis, its behavior and failure diagnostics, life assessment as well as structural revitalization. By applying the methods defined by this scientific discipline, it is possible to determine "weak" places in the structure, before crack occure and in the presence of a crack in structures that are exposed to a different types of loads. Assessing the integrity of rotary equipment, such as turbine shafts, is a particular challenge due to the nature of its load. Presence the crack makes the whole problem becoming even more complex and requires the inclusion of more scientific disciplines and tools, such as software packages that can simulate the working conditions of equipment, more precisely, dynamic load that can cause material fatigue of the structure. The topic of this doctoral dissertation is the research of the behavior of rotary equipment, specifically turbine shafts, Hydroelectric Power Plant "Đerdap II" in the presence of cracks with the aim of determining the integrity and remaining service life of turbine shafts. The danger in the presence of a crack with this type of equipment is the possibility of a brittle fracture which is, by its nature, unpredictable, and often with fatal consequences. Special attention in this study is dedicated to the places on the structure that cause stress concentration. The Abaqus and MORFEO software packages, i.e. the principles of the extended finite element method (eng. XFEM), were used to solve the problem of assessing the integrity of the rotary equipment of the hydroelectric shaft. As input data in application of XFEM method using aforementioned packages, experimental results obtained by using concept of elastic-plastic fracture mechanics i.e. application of the well-known Paris law with the aim of determining the fatigue crack growth rate are used. The data obtained by experimental tests, specifically the values of parameters C and m of the well-known Paris law, were the basis for numerical simulations of fatigue crack growth in the turbine shaft using the law of linear-elastic fracture mechanics. In addition, in this study, a stress analysis of the turbine shaft was performed, as well as a direct comparison of analytical and numerical results. The main goal of the entire study can be reduced to the explanation of the complex state and general behavior of the rotary equipment, i.e. the turbine shaft in the presence of cracks caused by fatigue load and in the presence of a stress concentrator. It can be pointed out that the main objective of this study is to determine the dependence of crack growth rate on crack size for a certain shaft geometry on the basis of which it is possible to estimate the integrity and life of the shaft, in addition to all known material properties. Indirectly, the developed and presented numerical models in this dissertation, as well as experimental procedures that have great applicability in integrity assessment of this type equipment,viii also provide scientific and engineering contributions of this study analysis, like determining integrity and remaining life of the equipment exposed to a fatigue load in the presence of a crack

Različiti pristupi za kreiranje geometrijskih modela anatomske osi femura i tijela femura

In today\u27s medicine, especially in the field of orthopedic surgery, it is very important to use geometrically accurate and anatomically correct geometrical models of human bones for the pre-operative planning and implants creation. In order to create such models, two new methods for geometrical modeling were developed and presented in this paper. These methods enable creation of femur anatomical axis and femur shaft geometrical models, and they are: GCM (Gravity Center Method), and CPM (Curve Projection Method). Both methods enable creation of geometrical models which are based on data acquired from the medical imaging devices (CT, MRI, X-Ray). The basic difference between these two methods and all the others is in the manner of generating the points through which anatomical axis model (3D curve) passes or goes near. The applied methods are developed considering the natural shape and anatomical landmarks of the femur bone, as well as standard CAD techniques for geometrical modeling which are common in engineering.U današnjoj medicini, osobito u području ortopedske kirurgije vrlo je važno koristiti geometrijski točne i anatomski ispravne geometrijske modele ljudskih kostiju za pred-operativno planiranje i kreiranje implantata. Radi kreiranja takvih modela dvije nove metode geometrijskog modeliranja su razvijene i prezentirane u ovom radu. Ove metode omogućuju kreiranje geometrijskih modela anatomske osi femura i tijela femura i one su: GCM (eng. Gravity Center Method), i CPM (eng. Curve Projection Method). Obje metode omogućavaju kreiranje geometrijskih modela koji se temelje na podacima dobivenih od medicinskih uređaja (CT, MRI, X-Ray). Osnovna razlika između ove dvije metode u odnosu na sve ostale je u načinu generiranja točaka kroz koje anatomska os modela (3D krivulja) prolazi ili je u blizini. Primijenjene su tehnike koje su razvijene uzimajući u obzir prirodni oblik i anatomske značajke femura. kao i standardne CAD tehnike za geometrijsko modeliranje koje su uobičajene u inženjerstvu

REVIEW OF BONE SCAFFOLD DESIGN CONCEPTS AND DESIGN METHODS

The paper brings out a review of existing, state-of-the-art approaches to designing the geometry of the scaffolds that are used for tissue engineering with a special emphasis on the macro scaffolds aimed for bone tissue recovery. Similar concepts of different authors are organized into groups. The focus of the paper is on determining the existing concepts as well as their advantages and disadvantages. Besides the review of scaffolds' geometry solutions, the analysis of the existing designs points to some serious misconceptions regarding the scaffold role within the (bone) tissue recovery. In the last section of the paper, the main requirements regarding geometry, that is, architecture and corresponding mechanical properties and permeability are reconsidered

Usporedba odziva modela pneumatika s detaljnim gaznim slojem i pojednostavljenog modela za analizu kotrljanja pneumatika u stacionarnom stanju

This paper deals with the level of detail that is necessary for representation of tread pattern in finite element tire models. Different methods for creation of tire tread mesh are systematized by two different criteria: the most common approaches and the finite element analysis type. Some of the representative approaches found in literature are given in more detail and their advantages and disadvantages discussed. An example from author’s experience, which describes the creation of finite element tire model with detailed tread for steady-state rolling analysis, is presented. The paper also brings a head-to-head comparison of the response of simplified and detailed tread tire models, subjected to a range of finite element analyses, from footprint analysis at static loading conditions to steady-state rolling cornering analysis.Ovaj rad se bavi razinom detalja koja je potrebna za prikaz šare gaznoga sloja u modela pneumatika namjenjenih analizi primjenom metode konačnih elemenata. Različite metode za izradu mreže konačnih elemenata su sistematizirane po dva različita kriterija: najčešćih pristupa i tipa analize primjenom metode konačnih elemenata. Neki od tipičnih pristupa koji se mogu naći u literaturi opisani su u više detalja i navedene su njihove prednosti i nedostaci. U članku je dat primjer iz iskustva autora, koji opisuje stvaranje modela pneumatika s detaljnim gaznim slojem za analizu kotrljanja u stacionarnom stanju. U radu je također prikazana izravna usporedba odziva pojednostavljenog modela pneumatika i modela s detaljnim gaznim slojem, podvrgnutih nizu analiza, od analize kontakta između tla i pneumatika pod statičkim uvjetima opterećenja do skretanja pri kotrljanju u stacionarnom stanju

Razvoj modela za predviđanje čvrstoćepri indirektnom zatezanju uzoraka napravljenih od struganog asfaltaprimenom mašinskog učenja

U okviru ovog rada razvijen je model za predviđanje čvrsoće pri indirektnom zatezanju (Indirect Tensile Strenght –ITS ) uzoraka struganog asfalta (Reclaimed Asphalt Pavement –RAP) baziran na metodama mašinskog učenja (Machine Learning –ML). Analiza glavnih komponenti (Principal Component Analysis –PCA) korišćena je kako bi se smanjio skup podataka koji opisuje granulometrijske sastave uzoraka RAP-a. Razvijeni su različiti modeli višestruke polinomne regresije (Multivariate Polynomial Regression –MPR) koji u obzir uzimaju karakteristike RAP-a (sadržaj i penetracija ostarelog bitumena, granulometrijske krive pre i posle ekstrakcije bitumena), postupak pripreme uzoraka (temperatura zagrevanja) i karakteristike uzoraka (sadržaj šupljina). Analiza je pokazala da se PCA tranformacija pouzdano može koristiti za smanjivanje skupa podataka o granulometrijskom sastavu (74% varijanse podataka opisanojesa prve dve glavne komponente). Takođe je zaključeno da najjednostavniji (linearni) model višestruke regresije pokazuje najveću tačnost od svih analiziranih modelasa koeficijentom determinacije 0.59, što se može smatrati visokim za dati skup podataka (više od 40 uzoraka RAP-a iz različitih izvora)

Procedure for Creating Personalized Geometrical Models of the Human Mandible and Corresponding Implants

The greatest challenge in engineering of human mandible implants lies in its customization for each patient individually, by adapting them to the patient's anatomical, morphological and physiological characteristics. This customization maximizes the efficiency of the patient's health recovery process. The application of anatomically shaped and personalized bone endoprosthesis, fixation plate and scaffold models bring great improvement to the clinical practice in maxillofacial surgery. It ensures that implant meets the biomechanical and dentofacial aesthetic requirements and, ultimately, reduces complications during recovery. In order to create such implants, novel procedure based on personalized models of mandible and its parts, and also plates and scaffold implants is presented in this paper. Design procedures for the creation of the personalized models are based on the application of Method of Anatomical Features, which has been already applied for the creation of geometrical models of human bones. This procedure improves pre-surgical planning, enables better execution of surgical intervention, and as a consequence improves patient recovery processes

Repair welding of pressure equipment with unacceptable defects

The paper describes non-destructive testing and the repair welding technology for eliminating defects in the pressure equipment of RHE BB (Bajina Basta) (located in Serbia). The obtained results had justified the proposed technology

Non-linear lateral buckling analysis of aluminium alloy channel beams

This research paper presents the comparative analysis of lateral-torsional buckling resistance of structural aluminium alloy members, accounting for the effects of initial geometrical imperfections. The results of non-linear numerical analysis, conducted using ABAQUS software, are compared with the results obtained by utilizing the procedure for calculation of LTB resistance suggested by EN 1999-1-1. The purpose of the analysis is the assessment of accuracy of the above-mentioned code-prescribed design method using the real Al channelsection members with initial imperfections on which the load does not act in the shear centre

Assessment of integrity of pressure vessels for compressed air

Fracture mechanics approach for structural integrity assessment is described in the case of pressure vessels for compressed air. The results of non-destructive testing indicated unacceptable defects on the vessels and set a base for application of failure analysis diagrams (FAD) and risk-based analysis. Risk matrix are applied with the aim of assessment and analysis of the integrity of the vessels