Application of the Functional Flow Diagrams in a Design of the Level Crossing Hydraulic Barrier Drive

In a domain of a safety increasing of railway and road traffic, hydraulic barrier drives installed at level crossings have an important role. Frequent traffic accidents at level crossings, involving road vehicles and trains, are result of inappropriately equipped level crossings with signalling and safety equipment. Limited use of hydraulic barrier drives is the result of complicated adaptation in the process of implementing such systems to the existing infrastructure of some of the equipment manufacturers and railway operators. Hydraulic barrier drive PBH21, which uses a modular architecture, was developed and designed in this paper. Applying modular design principles and functional modeling methods, using functional flow diagrams, PBH21 has ability to adapt on the technologies and infrastructures of other major manufacturers of such equipment within EU countries and other countries in the world that have developed railway infrastructure. Due to the protection of certain design solutions from competition, certain details are not presented in this paper

Implementation and Comparative Analysis of Mobile Phone Application for Learning and Teaching in Mechanical Engineering Education

Increasing student motivation and engagement in classroom (and during the study in general) is the aim of every lecturer. Never stopping development of new digital tools and media present a new challenge in the educational process. The goal of this research is to increase the knowledge and understanding of the influence of Bring Your Own Device (BYOD) approach (and use of the mobile devices in classrooms in general) on: teachers’ practice and students’ classroom activities, students’ attitude about bringing the mobile phones in the class and mobile phone applications in education processes. This research focuses on undergraduate and postgraduate mechanical engineering students. Personal reflection of the lecturers and online survey for students was used as a tool to investigate participants’ attitude towards mobile applications as a method of promotion of active learning in engineering education

Određivanje zaostalih naprezanja u rešetkastoj probi

Tijekom formiranja odljevka dolazi do pojave zaostalih naprezanja. Zaostala naprezanja uglavnom se pojavljuju zbog nejednakih volumenskih promjena i neistovremenih faznih i strukovnih promjena u različitim dijelovima odljevka. Ukoliko su naprezanja veća od vlačne čvrstoće, u proizvodnji ili uporabi, pojavit će se iskrivljenje ili pucanje odljevka. Da bi se izbjegle greške na odljevcima potrebno je znati kolika su zaostala naprezanja te da li ona prelaze dopuštena naprezanja. U radu su prikazana mjerenja zaostalih naprezanja u rešetkastoj probi pomoću uređaja DMD 20 i MTS 3000

Mjerenje zaostalih naprezanja u radijatorskom članku

Zaostala naprezanja uglavnom se pojavljuju zbog nejednakih volumenskih promjena i neistovremenih faznih i strukturnih promjena u različitim dijelovima odljevka. Ukoliko su naprezanja veća od vlačne čvrstoće, u proizvodnji ili uporabi, pojavit će se izvitoperenje ili pucanje odljevka. Da bi se izbjegle greške na odljevcima potrebno je znati kolika su zaostala naprezanja te da li ona prelaze dopuštena naprezanja. U radu su prikazana mjerenja zaostalih naprezanja u aluminijskom radijatorskom članku Solar 500 - 5A (EN 46100

Optimization of Parameters for Protection of Materials by Primer Application

The protective properties of coating systems usually depend on their base layer, since its characteristics and chemical composition are greatly responsible for prevention of corrosion development. Moreover, a good primer as a base coating has to provide good adhesion between the coating system and the substrate material, as well as good cohesion, i.e., coating strength. The described experiment aimed to determine the influence of input parameters (anticorrosive pigment content, conditioning time, dry film thickness) on the adhesion properties of the coating. The optimization of input parameters was achieved by the pull-off test in order to determine their maximum values. For the purpose of imitating aggressive atmosphere of service conditions, the experiment was run in a salt spray chamber, in which samples were cyclically sprayed with 5% sodium chloride (NaCl) solution for 120 h. The obtained mathematical model makes it possible to define the optimal values of the input variables for the defined values of the required property, i.e., the adhesion properties of the applied primer for certain exploitative conditions