Mechanical and Machining Properties Analysis of Al6061-Cu-Reinforced SiC_PMetal Matrix Composite

The metal matrix composite (MMC), despite of its high stiffness, strength, corrosion resistance, wear resistance, non-react with chemicals and so many other tailored qualities which are never obtained in alloy of metals, has limited utilization due to the high cost of fabrication. In this study, a modest attempt has been made to find out the process parameters at which best mechanical properties of Al6061, 4% Cu and reinforced 5% SiCP ceramic MMC can be obtained. The addition of 4% Cu in Al6061 is more or less comparable to the composition duralumin, which are widely used in aerospace applications. SiCP is hard and has linear thermal expansion at high temperature. With reinforcement of SiCP in Al6061-Cu alloy, it can be postulated that hardness of MMC retains at high temperature applications. An analysis of Variance (ANOVA) and linear regression was used for analysis of data with the help of SPSS (Version-17.0). Independent parameters are five levels of pouring rates (1.5 cm/s, 2.0 cm/s, 2.5 cm/s, 3.0 cm/s and 3.5 cm/s), and material type (Al6061 + 4% Cu alloy and Al6061 + 4% Cu, reinforced 5% SiCp MMC processed using stir casting technique) and dependent parameters are hardness and impact strength material removal rates of workpiece. It is found that at different pouring rates material hardness and impact strength of workpiece are highly significant but the material removal rate of workpiece is having no significance value. At pouring rate of 2.5 cm/s and 700℃ ± 5℃ pouring temperature, optimum values of hardness and impact strength are observed as compared to other values of pouring rates (1.5 cm/s, 2.0 cm/s, 3.0 cm/s and 3.5 cm/s). Material Removal rate for work pieces of Al6061 + 4% Cu alloy is less as compared to MMC. So it can be concluded that MMC has better machining ability compared to Al6061 + 4% Cu alloy. Material removal rate of Al6061 + 4% Cu, reinforced 5% SiCP MMC has maximum values at 1.5 cm/s pouring rate compared to 2.0 cm/s, 2.5 cm/s, 3.0 cm/s and 3.5 cm/s pouring rates. With reinforcement of 5% SiC trend of mechanical properties is same, but the hardness and impact strength of MMCs are increased by 25% and 20% respectively. Also it is observed from scanning electron microscopy (SEM) that at pouring rate 2.5 cm/s a better homogeneity can be obtained.

A Clean Technology for Future Prospective: Emission Modeling of Gas Based Power Plant

The aim of present research is to study the dispersion of air pollutants using the air quality model, AERMOD and to predict the impact of pollutants (PM10, NO2 and CO) at the receptor level released from Gas Based Power Plant (GBPP). The net-concentrations including monitored data plus predicted values of PM10, NO2 and CO would be increased from base value 75 to 77.61 μg/m3 with an increase of 3.48%, 22 to 26.66 μg/m3 with an increase of 21.18% and 428 to 538.37 μg/m3 with an increase of 25.79% respectively. The study of hill effect showed that it had profound impact upon the dispersion of pollutants and the ratio (with hill and without hill) of each pollutant was 3.89 for PM10 (24 hr), 2.40 for NO2 (24 hr) and 13.98 for CO (1 hr). The natural gas based plant not only decreases the pollution level but also reduces the hospital treatment cost and protects the public health. The modeling results suggest that the GBPP could be a clean technology as replacement of coal power plants located in the city which pollute the environment considerably in spite of control measures installed.

Removal of Fluoride from Groundwater by Carbonised <i>Punica granatum</i>Carbon (“CPGC”) Bio-Adsorbent

This study applies the development and application of low cost, Punica granatum bio-adsorbent for the removal of fluoride in groundwater. The batch adsorption study was carried out to analyze the defluoridation by contact time variation, adsorbent dose, adsorbate concentration, adsorbent particle size and presence of co-anions at neutral pH. The analysis of the isotherm equilibrium data using the Langmuir and Freundlich equations by linear methods showed that the data fitted better with Freundlich model (R2 > 0.980). Prepared adsorbent showed enhanced removal of fluoride concentration by 78.1% at equilibrium contact time of 75 minutes. Carbonised Punica granatum Carbon (CPGC) seeds showed a high affinity for fluoride ions compared with other conventional adsorbents. Therefore, it can be considered as a potentially “good”, low-cost bio-adsorbent for de-fluoridation of water compared to other bio-adsorbent.

A Cooperative Approach of Frequency Regulation Through Virtual Inertia Control and Enhancement of Low Voltage Ride-through in DFIG-based Wind Farm

Doubly-fed induction generator(DFIG)-based wind farms(WFs)are interfaced with power electronic converters.Such interfaces are attributed to the low inertia generated in the WFs under high penetration and that becomes prevalent in a fault scenario.Therefore,transient stability enhancement along with frequency stability in DFIG-based WFs is a major concern in the present scenario.In this paper,a cooperative approach consisting of virtual inertia control(VIC)and a modified grid-side converter(GSC)approach for low voltage ride-through(LVRT)is proposed to achieve fault ride-through(FRT)capabilities as per the grid code requirements(GCRs)while providing frequency support to the grid through a synthetic inertia.The proposed approach provides LVRT and reactive power compensation in the system.The participation of the VIC in a rotor-side converter(RSC)provides frequency support to the DFIG-based WFs.The combined approach supports active power compensation and provides sufficient kinetic energy support to the system in a contingency scenario.Simulation studies are carried out in MATLAB/Simulink environment for symmetrical and unsymmetrical faults.The superiority of the proposed scheme is demonstrated through analysis of the performance of the scheme and that of a series resonance bridge-type fault current limiter(SR-BFCL).

New Log-Domain First-Order Multifunction Filter Using MOSFETs in Weak Inversion

A new current-mode first-order log-domain multifunction filter is presented in this paper. This filter has single input and provides three outputs (low-pass, high-pass and all-pass) using a first-order low-pass filter and five of current mirrors as building blocks. The proposed filter employs only MOSFETs and a grounded capacitor. The first-order filters are used in audio and video applications extensively. The MOSFETs of the core section are operated in weak inversion thereby making the circuit suitable for low-voltage, low-power applications. The SPICE simulations have shown good performance of the proposed filter.

Effect of polycarboxylate type of super plasticizer on the hydration properties of composite cements

The work aims to study the effect of polycarboxylate type of super plasticizer on the hydration of composite cements.In this paper we have studied the hydration of 20 wt%fly ash(FA)blended Portland cement in the presence of 0.1 wt%super plasticizer(SP).Water consistency,setting times,non-evaporable water contents,compressive strength,water percolation,and air content measurements were carried out.In addition,Xray diffraction studies were carried out to understand the hydration process.The results indicated the increase in compressive strength of the FA blended Portland cement in the presence of SP and with the increase of the hydration time.