Experimental Characterization of Electrical Discharge Machining of Aluminum 6061 T6 Alloy using Different Dielectrics

Electrical discharge machining is a non-traditional machining method broadly employed in industries for machining of parts that have typical profiles and require great accuracy. This paper investigates the effects of electrical parameters: pulse-on-time and current on three performance measures (material removal rate, microstructures and electrode wear rate), using distilled water and kerosene as dielectrics. A comparison between dielectrics for the machining of aluminum 6061 T6 alloy material in terms of performance measures was performed. Aluminum 6061 T6 alloy material was selected, because of its growing use in the automotive and aerospace industrial sectors. The experimental sequence was designed using Taguchi technique of L9 orthogonal array by changing three levels of pulse-on-time and current, and test runs were performed separately for each dielectric. The results obtained show that greater electrode wear rate (EWR) and higher material removal rate (MRR) were achieved with distilled water when compared with kerosene. These greater EWR and MRR responses can be attributed to the early breakage of the weak oxide and carbide layers formed on the tool and alloy material surfaces, respectively. The innovative contributions of this study include, but are not limited to, the possibility of machining of aluminum 6061 T6 alloy with graphite electrode to enhance machinability and fast cutting rate employing two different dielectrics.Peer reviewe

Experimental and numerical investigations of free convection heat transfer in solar oven

The use of solar energy for baking, heating or drying represents a sustainable way of solar energy applications with negligible negative effects. Solar oven is an alternative to conventional oven that rely heavily on coal and wood or Electric oven that uses the power from the National grid of which the end users have little or no control. Since the Solar oven uses no fuel and it cost nothing to run, it use are widely promoted especially in situations where minimum fuel consumption or fire risks are considered highly important. As useful as the Solar Oven proved, it major setback in the area of applications has been its future sustainability. For the use of Solar Oven/Cookers to be sustained in the future, the design and development of solar oven must rely on sound analytical tools. Therefore, this work focused on the design and development of the solar oven. To test the performance of the Small Solar Oven a 5000cm3 beaker of water was put into the Oven and the temperature of the water was found to reach 810C after about 3hrs under an average ambient temperature of 300C. On no load test, the oven reached a maximum temperature of 112oC in 6hrs. In order to carry out the parametric studies and improve the performance of the Solar Oven, Mathematical models were developed and solved by using Characteristics-Based Split (CBS) Finite Element Method. The Model results were compared with the Experimental results and a good agreement ware found between the two results

Experimental and numerical prediction of extrusion load at different lubricating conditions of aluminium 6063 alloy in backward cup extrusion

In the present research work using a backward cup extrusion (BCE) die profile, different lubricating conditions on aluminum alloy AA6063 have been experimentally and numerically investigated to predict the extrusion load. It was obvious that due to an increase in applications of the extrusion process, many researchers have worked on the extrusion process using different methods to achieve their aims. This experiment was conducted with three different lubricants namely: Castor oil, Palm Oil and tropical coconut oil; as well as without lubricants. Different lubricating conditions were employed of varying strain rates ranges from 1.5×10-3s-1, 2.0×10-3s-1, 2.5×10-3s-1, and 3.0×10-3s-1; Numerical analysis and simulation for dry and lubricated conditions during extrusion load were also performed using DEFORM 3D software. The results show that prediction extrusion load increases with increasing strain rates. The maximum extrusion load was found to be higher for extrusion without lubricants. In all cases of strain rate, palm oil showed a lower extrusion load compared to the other lubricants. Castor oil indicated the highest extrusion load when the experiment was carried out using lubrication. There was a consistent agreement between the result gotten from the experiment and simulation results of the extrusion load-strike curve.Peer reviewedFinal Published versio

Kritik terhadap Sekularisme : Pandangan Yusuf Qardhawi

Since the first appearance until now, secularism had attracted the attention of many people: scientists, theologians, clergy, thinkers, and also by groups of religious studies. Due to the understanding had contains many irregularities, especially if this understanding entered to Islamic ideology. Because secularism was understood that was believed come from the West not from Islamic culture. Already so many scholars, scientists, and thinkers who devoted critical attention to secularism, one of them was Yusuf Qardhawi, who had a very good opinion in Islam rules, he was considered as a classic of science and a modern master in Islam, Qardhawi's criticism against secularism based on understanding of Islam. Based on the explanation above, the authors wanted to examine Yusuf Qaradawi's criticism against secularism, and in particular issues that would be discussed: the problems of Qardhawi's criticism against secularism, the reasons of Qardhawi in criticizing secularism, and the solution that was given in facingof secularism

Rasionalisasi Tafsir Ayat-ayat Mukjizat Kajian Tafsir the Holy Qur'an Maulana Muhammad Ali

Alquran telah menghasilkan kitab tafsir yang jumlahnya banyak sekali, setiap mufassir memiliki corak dan metode masing-masing dalam memahami ayat-ayat Alquran, Sehingga produk setiap kitab tafsir berbeda dengan dengan kitab tafsir yang lainnya. Maulana Muhammad Ali mencoba untuk menafsirkan ayat-ayat Alquran dengan metode yang berbeda dari para mufassir sebelumnya, yaitu lebih rasional, terutama ketika menafsirkan ayat-ayat yang Mutasya>bih. Walaupun sebelumnya telah ada para mufassir yang menafsirkan Alquran dengan rasional, seperti gurunya Muhammad Abduh dan Rasyid Ridha, namun Maulana Muhammad Ali lebih rasional bahkan lebih rasional dari Muktazilah. Disini penulis mencoba untuk mengkaji penfasiran Maulana Muhammad Ali dalam kitab tafsirnya The Holy Qur'an. Penelitian ini menggunakan Library Research yaitu dengan mengkaji penafsiran Maulana Muhammad Ali dalam kitab tafsirnya. Penulis juga membandingkan dengan para mufassir sebelumnya dan sesudahnya sehingga mendapatkan gambaran secara utuh bagimana metode yang dibangun oleh Maulana Muhammad Ali dalam menafsirkan ayat-ayat Alquran, apakah lebih rasional dari Muktazilah atau sama seperti penafsiran yang telah dibangun oleh mufassir sebelumnya. Hasil penelitian menunjukkan bahwa Maulana Muhammad Ali lebih rasional ketika menafsirkan ayat-ayat mukjizat dibandingkan dengan penafsir lainnya