The paper reports an analytical study of two problems of Rayleigh-Bénard convection(RBC): one in a Newtonian liquid occupying an axi-symmetric cylindrical enclosure(CE) and second in a two-dimensional rectangular enclosure(RE). Linear stability analysis is employed to obtain information on the onset of convection in terms of a critical Rayleigh number, Ra, as a function of the aspect ratio, Ro. The nature and the flow structures of the convective cells, at the onset of convection, are predicted theoretically by plotting the streamlines for different values of Ro. Not so shallow(Ro<1 or Ro≪1), and very shallow enclosures(Ro≫1) are considered. Concepts of cell-width and the wave number are respectively used in these two types of enclosures. An explicit analytical expression for the number of cells as a function of Ro is obtained theoretically. Exact prediction of the critical value of Ra, viz., Rac, as a function of Ro is also made. These are new findings in the case of both CE and RE. The fundamental differences between the problems of CE and RE are also highlighted.

This paper studied the natural convection heat transfer from two equal-sized cylinders of triangular cross-section confined in triangular enclosure. The inner cylinders have hot surfaces and the outer enclosure has a cold surfaces. The annular space between inner cylinders and the outer one was filled with incompressible Newtonian fluid. The work examined the behavior of fluid flow in the process of transferring heat energy. The work was achieved numerically using the commercial code ANSYS-CFX. The adopted initial conditions were selected for these ranges: Prantl number (Pr = 1 to 10³), Rayleigh number (Ra = 10³ to 10⁵). It was found that the increment of Ra number increases the rate of heat transfer. However, the effect of Pr number on heat transfer is almost negligible.

Recently, Electric Two-Wheelers ETW are changing the face of the global automotive market. This study focused on selecting proper material and mechanical isolation gap to design a protective enclosure for the battery pack of ETW. The integration of the Failure, Modes, Mechanism and Effect Analysis (FMMEA) method is utilized to develop the interface matrix and the severity index of different components of the enclosure. By analyzing different forces from the road conditions, dynamics during turn, acceleration, and deceleration with the enclosure, it becomes a crucial load-bearing element. Employing Finite Element Modeling (FEM), structural strength using materials like AL6061, Q235, C22000, DC 01 and Teflon are assessed under varying static, dynamic and thermal conditions. Modal analysis is conducted to observe the excitation frequencies where the maximum deformation for the metal enclosure is observed beyond 500Hz. AL6061 material that can withstand the stresses and deformations that are under allowable stress limits with negligible deformation is most preferable material based on the results. Minimal of 2.5 mm gap to be provided in case of metal casing and 10mm in case of Teflon is proven.

The decade of research concentrating on the area of Easter Slavonia revealed abundance of large on complex late Neolithic sites. It changed profoundly how we perceive late Neolithic settlement and space size and organization. As s first step in particular site detection we mostly conducted aerial reconnaissance and satellite image analysis but also data from the field such as excavation. On detected potential sites we conducted intensive field surveys and confirmed the attribution to the late Neolithic by surface finds. On those confirmed sites in the vicinity of Đakovo, Croatia, magnetic survey was conducted on 5 sites so far and the results confirmed presence of large scale late Neolithic settlements with complex spatial organization and enclosure(s). Most complex remains so far is site Gorjani Kremenjača and Topole which we present in this paper where a remains of one or two settlements covers the area of 70 hectares and is currently in the process of formal protection as a cultural landscape by the Ministry of Culture and Media of the Republic of Croatia. Special focus of the paper is the application of remote sensing in detection, archaeological confirmation and protection of the position Gorjani Topole.