Nano fluids are widely used today for various energy-related applications such as coolants, refrigerants, and fuel additives. New coolants design modifications being explored due to renewed interest in improving the working fluid properties of heat exchangers. Several studies have investigated nanofluids enhance radiator exchanger performance. A new class includes single, binary, tertiary nanop...

In this paper we present explicit formulas for the eccentric connectivity index of three classes of chain hexagonal cacti. Further, it is shown that the extremal chain hexagonal cacti with respect to the eccentric connectivity index belong to one of the considered types. Some open problems and possible directions of further research are mentioned in the concluding section.

Transformation optics (TO) concept well known for its huge possibility in patterning the path of electromagnetic waves is exploited to design a beam steering lens. The broadband directive in-phase emission in a desired off-normal direction from an array of equally fed radiators is numerically and experimentally reported. Such manipulation is achieved without the use of complex and bulky phase s...

A severe technical drawback of geothermal heat pumps (GHPs) is the fact that the nominal operating temperature available for domestic space heating is typically in the region of 50°C. This is 25°C to 40°C less than conventional boiler settings used in hydronic central heating applications. As a result, GHPs are not generally ideal for direct replacement of conventional hydronic central heating ...

Ultra-wideband (UWB) technique has become one of the most fascinating technologies with various antennas. It has the merits of high speed transmission rate, low power consumption and simple hardware configuration over conventional wireless communication systems. The research and development of the UWB systems including antennas have been widely performed [1-5]. Recently, UWB systems have focuse...

We predict the number of hexagonal systems consisting of 24 and 25 hexagons to be H 24 = 122237774262384 and H 25 = 606259305418149, with 6 and 5 signiicant digits, respectively. Further estimates for H n up to n = 31 are also given. Informally speaking, a hexagonal system can be viewed as a connected arrangement of hexagonal cells packed in the same way as the typical honeycomb arrangement in ...

Non-ionizing terahertz imaging using solid-state integrated electronics has been gaining increasing attention over the past few years. However, there are currently several factors that deter the implementations of fully-integrated imaging systems. Due to the lack of low-noise amplification above fmax, the sensitivity of THz pixels on silicon cannot match that of its mm-Wave or light-wave counte...

A fixed shaped beam antenna offers an excellent compromise between cost and system performance in high data rate systems operating in the frequency range of 565 GHz. Shaped Dielectric Lenses perform the task of collimation and shaping, along with physically small feed antennas, to obtain multiple and shaped beams in a fixed set of directions. Lenses are inherently broadband, easy to fabricate, ...

PURPOSE The purpose of this study was to assess the precision at the implant interface of gold-machined UCLA-type abutments and computer-assisted design and manufacture (CAD/CAM) titanium abutments with both external-hexagonal connection and internal-hexagonal connection. MATERIALS AND METHODS Fifteen gold-machined UCLA-type abutments with external-hexagonal connection, 15 gold-machined UCLA-...