Nucleate pool boiling heat transfer coefficients of Al2O3-water and TiO2-water nanofluids have been experimentally measured on three horizontal tubes with different materials and similar roughness under atmospheric pressure. Results revealed that the presence of nanoparticles in the base fluid leads to an increase in pool boiling heat transfer coefficients on stainless steel and brass tubes in ...

Bridge grafting (15 mm) into the sciatic nerve of SD rats was carried out using tendon chitosan tubes having either a circular or triangular cross-section, as well as triangular tubes combined with laminin, CDPGYIGSR, or CSRARKQAASIKVAVSAD (n = 15 in each group). As a control, isografting (15 mm) was carried out in the SD rats (n = 7). Specimens were taken after 1, 2, 4, 6, and 8 weeks for hist...

We have developed an electroformed copper lining having highly clean and smooth surface (i.e. little outgassing and high conductive copper) for use in accelerator components. The copper lining is produced by periodic current reversal electroforming with a low copper-content acid copper sulfate bath containing the specified amount of chloride ions (PR process). Deposit by PR process has the same...

The main objective of this research is to improvethe design and performance of the polyurethane foam-filled thin-walled aluminum grooved circular tubes using multi-response optimization (MRO) technique. The tubes are shaped with the inner and the outer circular grooves at different positions along the axis. For this aim, several numerical simulations using ABAQUS finite element explicit code ar...

the role of some ring structures in the distribution of porphyry copper deposits in south kerman porphyry copper belt is discussed. in the study area, ring structures are circular or elliptical shaped features which are partly recognized on satellite images. in this study, landsat multispectral images were used to identify ring structures in the area. the rudimentary identification stages of th...

In this paper, cyclic flaring and sinking (CFS) as a new severe plastic deformation (SPD) method was employed to produce the ultrafine grain (UFG) copper tubes. The extra friction has eliminated in the CFS method that provided the possibility for production of longer UFG tubes compared to the other SPD methods. This process was done periodically to apply more strain and consequently finer grain...

In this paper, convection heat transfer of Al2O3-water nanofluid turbulent flow through internally ribbed tubes with different rib shapes (rectangular, trapezoidal and semi-circular) is numerically investigated. For each rib shape, the optimum geometric ratio and volume fraction were calculated using entropy generation minimization technique. The governing equations in...

Application of nanofluid and coiled tubes are two passive methods for increasing the heat transfer. In the present study, the turbulent flows of water and nanofluid in coiled tubes heat exchanger were numerically studied. CuO-water nanofluid containing 1 vol% copper oxide nanoparticles was used and single-phase approach was considered for nanofluid flow. The effect of different geometrical para...

In this research, the heat transfer coefficient (HTC) and pressure drop of alternating cross-section flattened (ACF) tubes were investigated experimentally compared with same parameters a circular tube. Three different ACF fabricated from copper tubing an internal diameter 4.5 mm, thickness 1 length 400 mm. The twist angles 30, 45, 90°. experimental ranges covered mass flux 729–1,434 kg/m2s 12–...

SUNITA SINGH, m.b., b.s. (Punjab) From the Brigade Laboratory, Allahabad Instead of the ordinary rectangular rack, a circular rotary rack has been used by us. The experimental tubes are rotated alongside the control tubes. The light comes from below after being reflected from a black surface. The readings are very clear and can be quickly made without disturbing the tubes. The rack consists of ...