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An investigation was conducted for heat transfer characteristics of binary magnetic uid ow in a partly heated circular pipe experimentally. The boiling heat transfer characteristics on the effects of the relative position of the magnetic eld to the heated region were particularly considered in the present study. F rom the experimental veri cation, the N usselt number, representing boiling heat transfer characteristics, was obtained for various ow and magnetic conditions which were represented by the non-dimensional parameters of the R eynolds number and the magnetic pressure number. Additionally, the rate of change of the N usselt number found by applying the magnetic eld was also estimated and the optimal position of the eld to the partly heated region was discussed. The results indicated that the effect of the magnetic eld to the heat transfer rate from the heated wall was mainly subjected to the effect of the vortices induced in the magnetic eld region and the possibility of controlling the heat transfer rate by applying an outer magnetic eld to utilize the effect. Keywords: magnetic uid, heat transfer, boiling two-phase ow NOTATION C p0 speci c heat of the uid at the representative temperature D inner diameter of the ow pipe and the test sectionˆ0.01 m D 0 outer diameter of the test sectionˆ0.05 m G mass owrate (kg/s) h heat transfer coef cient H r radial component of the magnetic eld H z axial component of the magnetic eld L length of the heated wallˆ0.1 m M max magnetization of the uid at the eld H max M r radial component of magnetization M s saturation magnetization of the uid at the representative temperature M z axial component of magnetization N u average N usselt number N u…z ‡ † local N usselt number for z ‡ p pressure of the uid (Pa) Pr Prandtl number Q total heat transfer from the heated wall to the uid R e R eynolds number R p the magnetic pressure number T in temperature of the uid at the inlet of the test sectionˆ327 K (representative temperature) T w temperature of the heated wallˆ377 K T w, in mean temperature of the inner wall of the test section T w, out mean temperature of the outer wall of the test section u speci c internal energy (J/kg) U in mean velocity of the uid at the inlet of the test section z ‡ non-dimensional length from the inlet of the test sectionˆ…z=D †=…Re=Pr † Dc distance from the centre of the heated region to the distribution centre of magnetic eld DN u m rate of change of the average N usselt number after applying the magnetic eld l 0 heat conductivity of the uid at the representative temperature l B heat conductivity of brassˆ118 W/m K

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The new mechanical joint of the small size pipe piles applied to the foundation of residential structures was proposed. Investigating the strength of the mechanical joint, loading tests (compression test and torsion test) and FEM analysis were carried out. As a result of these investigations, the mechanical joint has grater compression and torsion strength than that of required value. In consequence, it is confirmed that the proposed joint satisfy the required performance as a major conclusion.

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