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Water pollution has become a serious issue of this century due to increased industrialization. Several methods have been adopted to tackle this issue, including adsorption by activated carbon (AC). Conventional sources of AC preparation are costly and non-renewable as well. Several fruit and agricultural wastes have characteristics to become sustainable feedstock for AC preparation. This study aims to prepare cost effective AC from sustainable raw material, cow dung. The preparation has been analyzed and optimized by utilizing central composite design (CCD). The effect of activation temperature, time, and impregnation ratio (IR) on responses of percent yield ( R1) and percent pesticide removal (R2) has been analyzed. Quadratic models have been suggested with R2, adjusted R2, and predicted R2 values of 0.98, 0.96, 0.89 for R1, and 0.97, 0.94, 0.87 for R2, respectively. Activation temperature and KOH/Feedstock ratio significantly influence the yield and pesticide removal. Optimized conditions of activation temperature, KOH/Feedstock ratio, and activation time are 708.07 °C, 1.22 and 0.66 h, respectively. These conditions produced 14.78% yield and 89.18% pesticide removal. SEM and BET analysis of optimized AC also confirmed porosity development and large surface area availability due to activation process. Findings of this study suggest that cow dung can be used to prepare low-cost AC for pesticide removal from aqueous solution.

This case study aims toward the importance of the application of rapid prototyping and tooling technology in die design and manufacturing. Many conventional machining processes of die manufacturing, including computer numeric control (CNC) machining and electric discharge machining (EDM), are used by the local manufacturers of die, but these processes are time-consuming and expensive. There is a need to explore opportunities to reduce die manufacturing costs. This paper aims to assist the development of low-cost dies through the application of rapid prototyping and tooling technology. For this purpose, solid works software was used to design the die of a 4-hole Lego Block. 3D printing was incorporated in the existing capability of investment casting process for die manufacturing. A proper gating system design consideration was taken into account to ensure the accurate flow of casting material for achieving fine surface finish. From the results, it has been observed that gating system design with four ingates gives the optimum value of surface finish (~3.4156μm). The proposed rapid prototyping and tooling technology makes the practitioners (tool makers) capable of making dies with complex shapes, superior surface finishes, and dimensional accuracy in less or no time.

This study aims to evaluate the microstructure and mechanical behavior of aluminum 2024 and stainless steel 304 dissimilar joints. The gas tungsten arc welding (GTAW) process has been employed to weld base metals by inserting copper-nickel-based (Cu-10%Ni) filler metal. The effects of GTAW parameters such as welding current, welding speed, and gas flow on microstructure and tensile strength have been analyzed through the Taguchi method. Results revealed that tensile strength is primarily influenced by welding current, followed by speed and gas flow rate. The excellent joint strength of 138 MPa has been achieved by using Cu-10%Ni filler metal. The optimal combination of parameters, i.e., welding current of level 2 (80 A), welding speed of level 1 (100 mm/min), and gas flow rate of level 3 (10 l/min), has been obtained through SN ratio optimization. Microstructure and EDS analysis depicted that the weld zone of a high-strength joint contained fine dendrites and CuAl and NiAl solid solutions, while the weld zone of a low-strength joint featured coarse dendrites and brittle FeAl phases.

It is a requirement of modern age industries, especially the aerospace, automobile, and shipbuilding sectors, to manufacture high strength and low weight dissimilar aluminium alloy welded joints. Therefore, the aim of this project is to investigate the effect of tool rotation speed, feed rate, and pin type on the ultimate tensile strength (UTS) of dissimilar aluminium alloys (2024 Al and 5754 Al) in friction stir welded joints. Nine experiments have been performed using an orthogonal array (L9) of the Taguchi method. An analysis of variance (ANOVA) established that pin type is the most prominent parameter, followed by tool rotation speed and feed rate. The optimal value of ultimate tensile strength (268 MPa) was achieved at 1.5 mm/s feed rate, 1600 rpm speed, and type 1 of pin. A confirmation test shows that there is a high correlation between the estimated and actual values of UTS.

In recent years, the reliable, accurate, and timely estimate of product cost at the conceptual design stage can enhance the competitiveness of a casting part. Set‐based concurrent engineering has emerged as an efficient solution to overcome this limitation as it provides simultaneous design procedures to positively assist the designer in achieving the required customer values in a short time and low cost. Therefore, this study attempts to integrate the set‐based concurrent engineering methodology into the development of a cost modeling system for the metal casting process. The system architecture is comprised of a user interface, knowledge database, and CAD modeling system. A detailed working flow process of the developed cost modeling system has been proposed under the guidelines of set‐based concurrent engineering. Further, the proposed methodology is demonstrated and validated by employing a real‐time casting part that was manufactured using the sand casting process. The implementation of the system provided many tangible benefits to the collaborative company including a decrease in cost estimation time (∼50%) and part rejection rate (∼32.3%). Further, the developed cost modeling approach provided a cost estimate near the actual cost of the product (∼4% deviation). It truly proves the significance of the developed system for the practitioners who believe that accurate and timely estimates of product manufacturing cost at the design stage can enhance the competitiveness of a product. [ABSTRACT FROM AUTHOR]

Al7075-Cu composite joints were prepared by the squeeze overcast process. The effects of melt temperature, die temperature, and squeeze pressure on hardness and ultimate tensile strength (UTS) of squeeze overcast Al7075-Cu composite joints were studied. The experimental results depict that squeeze pressure is the most significant process parameter affecting the hardness and UTS. The optimal values of UTS (48 MPa) and hardness (76 HRB) are achieved at a melt temperature of 800 °C, a die temperature of 250 °C, and a squeeze pressure of 90 MPa. Scanning electron microscopy (SEM) shows that fractured surfaces show flatfaced morphology at the optimal experimental condition. Energy-dispersive spectroscopy (EDS) analysis depicts that the atomic weight percentage of Zn decreases with an increase in melt temperature and squeeze pressure. The optimal mechanical properties of the Al7075-Cu overcast joint were achieved at the Al2Cu eutectic phase due to the large number of copper atoms that dispersed into the aluminum melt during the solidification process and the formation of strong intermetallic bonds. Gray relational analysis integrated with the Taguchi method was used to develop an optimal set of control variables for multi-response parametric optimization. Confirmatory tests were performed to validate the effectiveness of the employed technique. The manufacturing of squeeze overcast Al7075-Cu composite joints at optimal process parameters delivers a great indication to acknowledge a new method for foundry practitioners to manufacture materials with superior mechanical properties. [ABSTRACT FROM AUTHOR]