Application of TOPSIS Method for Prediction of Optimum Design Parameters of Micro Hole Textured Cutting Inserts in Turning of Al-MMC

Metal Matrix Composite (MMC) has better mechanical properties and it is possible to produce near net shape. Aluminum-based MMC (Al-MMC) has challenges in terms of machinability studies and estimation of its optimum process parameters. Alternative cutting fluid research is a challenging area in machining. To avoid, existing hydrocarbon oil-based cutting fluid, textured inserts embedded with a solid lubricant are one of the alternative solutions. Micro hole textured inserts make a hole on the rake face of the cutting tool inserts. Texture includes various important design parameters namely hole diameter, hole depth and pitch between the holes. These optimum parameters influence the machining process. In this work, the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) method is used to find the optimum design parameters (hole diameter, hole depth and pitch between holes) during turning of Al- MMC. The objective parameters considered are minimization of surface roughness, power consumption and tool flank wear. The optimum combination of these design parameters is obtained by the higher relative closeness value of the TOPSIS method. The result of the investigation revealed that these design parameters are important to obtain improved machining performance. Also, it is understood that the TOPSIS method has an appropriate procedure to solve multiple objective optimization problems in manufacturing industries.

Application of a Single Porous Basket as a Pier Scour Countermeasure

This paper presents a study on bridge pier protection with a single porous basket (SPB) in clear-water experiments. The SPB is a type of combined flow-altering countermeasure. The SPB was installed at a distance ahead of the protected pier. After a series of tests, the results showed that appropriate installation of the SPB was able to effectively adjust the flow pattern to reduce the down-flow motion and horseshoe vortex ahead of the pier. Dominant factors for the pier protection—considered for all tests—included the distance between the basket and pier, submerged depth of the basket, basket length, pier diameter, basket diameter, hole size, porosity, and the flow approaching angle. After evaluating these parameters through laboratory tests, the results of protection were optimized. In optimal conditions, the SPB was able to provide maximum pier protection and decrease the maximum scour depth by as much as 75.53%.

Leakage through a hole in a geomembrane beneath a fine-grained tailings

Leakage through a 10-mm-diameter hole in a geomembrane beneath fine-grained tailings is examined for a range of pore pressures and effective stresses. Leakage was measured in an experiment with coupled physical and hydraulic conditions to simulate the effective stresses and flow conditions near the hole. The leakage rate was at little as 0.16 L/day with 200 kPa pore pressure (10-30 kPa effective stresses) and increased only to 0.46 L/day with 800 kPa pore pressure (200 kPa effective stress). Seepage analysis of the experiment and local measurements of permeability from small samples extracted after the experiment indicate that the tailings hydraulic conductivity controlling flow was 3–6 x10-9 m/s. Only a subtle decrease in hydraulic conductivity (less than 2 times) near the hole was found. No evidence of seepage induced migration of fines within the tailings was found. Calculations with the parameters deduced from the experiment show that leakage from a tailings storage facilities containing fine-grained tailings can be limited to 1-2 L/ha/day with a geomembrane liner, even when containing up to five 10-mm-diameter holes per hectare, as opposed to an unlined facility with 3 to 4 orders of magnitude more leakage.

Demonstration of a MOT in a sub-millimeter membrane hole

We demonstrate the generation of a cold-atom ensemble within a sub-millimeter diameter hole in a transparent membrane, a so-called “membrane MOT”. With a sub-Doppler cooling process, the atoms trapped by the membrane MOT are cooled down to 10 $$\upmu$$ μ K. The atom number inside the unbridged/bridged membrane hole is about $$10^4$$ 10 4 to $$10^5$$ 10 5 , and the $$1/e^2$$ 1 / e 2 -diameter of the MOT cloud is about 180 $$\upmu$$ μ m for a 400 $$\upmu$$ μ m-diameter membrane hole. Such a membrane device can, in principle, efficiently load cold atoms into the evanescent-field optical trap generated by the suspended membrane waveguide for strong atom-light interaction and provide the capability of sufficient heat dissipation at the waveguide. This represents a key step toward the photonic atom trap integrated platform (ATIP).

Membrane MOT: Trapping Dense Cold Atoms in a Sub-Millimeter Diameter Hole of a Microfabricated Membrane Device

We present a demonstration of keeping a cold-atom ensemble within a sub-millimeter diameter hole in a transparent membrane.Based on the effective beam diameter of the magneto-optical trap (MOT) given by the hole diameter (d = 400 μm), we measurean atom number that is 105 times higher than the predicted value using the conventional d6 scaling rule. Atoms trapped bythe membrane MOT are cooled down to 10 μK with sub-Doppler cooling. Such a device can be potentially coupled to thephotonic/electronic integrated circuits that can be fabricated in the membrane device representing a step toward the atom trapintegrated platform.

Optimization of Hole Diameter on Fins of Si Engine through Numeraical Analysis

Fuel and material cost is increasing day by day in all the industries. In IC engine, engine fails mainly due insufficient of heat transfer from the cylinder wall to the atmospheric air. In SI engine, heat is extracted from the cylinder wall by convection heat transfer through the fins. In this paper optimal hole size on the fins is obtained in order to extract the heat from the engine by numerical method. ANSYS is used to find the temperature distribution on the fins , when there no holes, when there is hole diameter as 2mm, 2.5mm,3 mm, 3.5mm,3.8mm, 4mm and two row holes of 3.5 mm diameter. For this analysis fluid flow (fluent) is chosen, air is circulated on engine with 16.666 m/s velocity and with atmospheric pressure. Temperature value of 800K is applied to the cylinder wall. Temperature is compared with the all hole diameter cases, and it is found that the 3.5 mm diameter hole gives the best results compare to all other hole diameter. The temperature difference 0.04K is obtained between without holes and with 3.5 mm diameter. The 3.5 mm diameter hole fins are used where material cost goes at high rate.