Search

This paper presents the parametric performance of channels formed in the experimental run of stir welding and its effect with respect to the traverse speed (TS) and rotary speed (RS) over the two dissimilar aluminium amalgams i.e., Al6082 and Al2024. In the experimentation it was observed that the parametric performance and effect of RS over channel area was inversely proportional to the TS with respect to valuated array of experimental data. During friction stir welding of dissimilar aluminium amalgams, geometry of void defects can be regulated to optimum with the systematic arrangement of processing parameters. The effect of TS and RS are indistinguishable throughout the cross sectional area of welded channel. The shape and size of produced friction stir channels were found to be strongly dependent on process parameters i.e., TS and RS. At constant RS of 1000 rpm the increase in TS from 50 mm /min to 100 mm/min changed the shape of channel from isosceles trapezium to triangular. Similar effect was observed for increase in RS.

Many industries requires higher cooling rate for equipment which intern affects the life and efficiency of the equipment. However fluids have limited rate of heat transfer through material. Has limitation for developing higher amount of heat transfer per unit time for cooling purpose. Nano fluids are prepared by separating nano particles in base fluid such as water, oil etc. which is used for higher amount of heat transfer per unit time. Innovative heat transfer fluids are synthesized by suspending metal oxide nano size solid particles. Experiments on nanofluid shown that it has higher thermal conductivity compared to its base fluid. These nano sized particles which are suspended in fluid changes thermal motion between different particles of fluid which increases the amount of heat transfer per unit time. As can be seen from the literature extensive research work is done on aluminium oxide–water and Copper oxide–water nano fluids. In this research utilized nanoparticles as CuO (copper oxide) as it has enormous thermal conductivity, had prepared CuO nanoparticles followed by nanofluid preparation. This article deals entirely about Copper oxide nanofluid with distilled water as base fluid, sodium dodecyl sulphate as surfactant and the percentage increment of amount of heat transfer per unit time of nano fluid is higher than that of base fluid and sample size found by X-Ray diffraction (XRD).

Aims and Objectives: This study aimed to evaluate the effects of at-home and in-office bleaching on the shear bond strength (SBS) of metal, ceramic, and composite orthodontic brackets and to compare their SBSs. Subjects and Methods: A total of 96 human lower premolar teeth were used for this study. Six teeth were used for scanning electron microscopic study while the remaining ninety were divided into three equal groups. Each group was further subdivided into three subgroups with ten samples each. Three protocols were used. In the at-home bleaching group (n = 30), opalescence non-PF (potassium nitrate and fluoride) bleaching agent (10% carbamide peroxide) was applied onto the teeth daily for 14 days and left for 8 h each day. Teeth in the in-office group (n = 30) were treated twice in consecutive days with Opalescence boost PF (40% hydrogen peroxide). After bleaching, the specimens were stored in distilled water for 1 day before bonding. SBS testing was performed on all teeth using Instron universal testing machine. Results: Analysis of variance indicated a significant difference (P < 0.005) among the groups. Maximum SBS was shown by ceramic brackets in control group (Ib) and minimum was shown by composite brackets of in-office bleached group (IIIc). Conclusions: The results showed that at-home bleaching did not affect the SBS significantly whereas in-office bleaching reduced SBS of metal, ceramic, and composite brackets significantly. It is preferable to use metal or ceramic brackets than composite brackets for bonding 24 h after bleaching.