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All Journal Jurnal Sains Materi Indonesia Jurnal Kimia dan Kemasan Jurnal Teknik Mesin EPI International Journal of Engineering Journal of Materials Exploration and Findings Recent in Engineering Science and Technology
Yudha Pratesa
Department Of Metallurgy And Materials Engineering, Universitas Indonesia
Aerospace Engineering Automotive Engineering Chemical Engineering, Chemistry & Bioengineering Chemistry Civil Engineering, Building, Construction & Architecture Computer Science & IT Control & Systems Engineering Electrical & Electronics Engineering Engineering Industrial & Manufacturing Engineering Materials Science & Nanotechnology Mechanical Engineering

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Pengaruh Waktu Pencelupan Proses Electroless Plating Terhadap Pembentukan Lapisan Tembaga Antibakteri Pratesa, Yudha; Noviardi, Luthfi; Fadlilah, Muhammad; Iqbal, Adimas Habib; Rizkia, Vika
Jurnal Kimia dan Kemasan Vol. 40 No. 1 April 2018
Publisher : Balai Besar Kimia dan Kemasan

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (644.902 KB) | DOI: 10.24817/jkk.v40i1.3598

Abstract

Penyebaran penyakit oleh bakteri sangat rentan menjadi wabah di rumah sakit dan fasilitas umum melalui kontak secara langsung dan tidak langsung. Kontak secara tidak langsung terjadi  melalui alat perantara seperti jarum suntik, pakaian hingga gagang pintu. Salah satu bagian yang paling sering disentuh orang adalah gagang pintu dan kusen. Saat ini, banyak kusen yang dibuat dari bahan dasar logam aluminium karena harga yang murah, tahan korosi dan ringan. Kusen aluminium umumnya diproses anodisasi untuk memberikan efek warna karena kesukarannya jika dicat secara langsung. Produk anodisasi umumnya berstruktur pori sehingga dapat menjadi tempat ideal tumbuh dan berkoloni bakteri dengan mudah. Pada penelitian dilakukan pembuatan lapisan tembaga yang menutup pori dan mampu memberikan efek racun pada bakteri Escherichia Coli penyebab berbagai macam penyakit. Hasil dari penelitian ini menunjukkan, waktu electroless plating optimal selama 26 menit yaitu ketebalan antara 8-24 µm. Tembaga berhasil melapisi permukaan material secara merata. Hasil pengujian antibakteri dengan Kirby test menunjukan hasil plating memiliki kemampuan untuk mencegah pertumbuhan bakteri. Hasil uji ketahanan lapisan terhadap cuaca menggunakan saltspray menunjukan pelapisan selama 26 menit memberikan efek yang terbaik.
Role of Flow Simulation as a Tools for Failure Analysis Induced by Sulphate-Reducing Bacterial Yudha Pratesa; Badrul Munir
EPI International Journal of Engineering Vol 1 No 1 (2018): Volume 1 Number 1, February 2018
Publisher : Center of Techonolgy (COT), Engineering Faculty, Hasanuddin University

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Abstract

Sulphate Reducing Bacterials (SRB) is one of the challanging problem in oil and gas. It could attack the metals to form a pit. The SRB ussually left a colony as the indication of corrosion attack. One of the main problem to prevent the corrosion attack is the ablitity to mapping the possibility of attacking area. However, this study offer a method to simulate the bacterial growth area based on the differential flow rate in the pipe. The flow simulation showed the ability to be used as the analytical tool for the bacterial growth mappings. Laboratory testing was also conducted for confirmation of the SRB presence in the system
EFFECT OF H2O2 AND MnO2 AS OXIDATORS OF GOLD AND COPPER LEACH PROCESSES FROM PRINTED CIRCUIT BOARDS Yudha Pratesa; Aji Wibisono; Wahyuaji Narottama Putra; Yunita Sadeli; A. Zakiyuddin; Sri Harjanto
Jurnal Sains Materi Indonesia Vol 20, No 3: APRIL 2019
Publisher : Center for Science & Technology of Advanced Materials - National Nuclear Energy Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (794.453 KB) | DOI: 10.17146/jsmi.2019.20.3.4710

Abstract

In general, electronic waste management in the form 2 of printed circuit boards (printed circuit boards/PCBs) is carried out by the process of removing components and taking precious metals that are easily recycled. However, in Indonesia, the recycling process for extracting precious metals has not been much processed, even though they contain precious metals such as copper and gold. This research was conducted to find a more economical and environmentally friendly treatment process by using an oxidizer of Hydrogen Peroxide (H2O2) and Manganese Oxide (MnO2) and reducing the level of HCl used. Observation of metal leaching results using Atomic Adsroption Spectroscopy (AAS) showed the value of recovery (recovery) of gold and copper reached 59.1% and 59.8% for 0.5M HCl + 2.5% H2O2. However, the recovery value of copper has reached its optimum point at the addition of 1.5% H2O2. The use of 3% & 5% MnO2 results in recovery values of 12% and 24% for gold and copper. Observation of the cross section shows the dissolution of the copper metal from the PCB and accompanied by a change in the color of the solution from clear to green, the more concentrated the more the amount of dissolved copper metal shows the characteristic of CuCl solution. The results of the comparison of the two types of oxidizers show that H2O2 is better than MnO2 in producing higher Cu and Au metals more than 3 times.
Studi Pemanfaatan Estrak Daun Pegagan untuk Inhibitor Korosi Ramah Lingkungan untuk Material API 5CT J55 di Lingkungan Air Formasi Yudha Pratesa; Andika Purnawidhi; Nuringtyas Rahwinarni
Jurnal Teknik Mesin Vol 7, No 1 (2018)
Publisher : Universitas Mercu Buana

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22441/jtm.v6i4.2178

Abstract

Daun Pegagan (Centella asiatica) pada awalnya dianggap sebagai tanaman pengganggu dan tidak bernilai ekonomis. Namun, hasil beberapa penelitian menunjukan manfaat daun ini sebagai obat karena memiliki kandungan fenolik dan anti oksidan. Karena bersifat anti oksidan, daun pegagan dinilai memiliki kemampuan untuk bekerja sebagai inhibitor korosi ramah lingkungan. Studi ini akan menguji kemampuan ekstrak Daun Pegagan sebagai inhibitor untuk baja API 5CT J-55 di lingkungan air formasi menggunakan pengujian polarisasi tafel, kehilangan berat (weigth loss) dan Fourier Transform Infrared Radiation (FTIR). Senyawa aktif antioksidan yang berperan untuk menginhibisi korosi akan diinvestigasi melalui pengujian FTIR  dengan melihat potensi gugus yang terbentuk. Variabel yang digunakan adalah konsentrasi inhibitor, yaitu 0 ppm, 100 ppm, 250 ppm, 500 ppm, dan 1000 ppm. Ekstrak daun pegagan yang mempunyai gugus fenolik merupakan inhibitor jenis campuran, dan dominan anodik. Efisiensi inhibisi paling tinggi didapatkan dengan konsentrasi 250 ppm. Inhibitor ekstrak daun pegagan dapat digunakan sebagai alternative inhibitor ramah lingkungan untuk baja J55 pada lingkungan air formasi
Pemanfaatan Campuran Myrmecodia Pendans dan Piper Crocatum Sebagai Green Corrosion Inhibitor pada Inhibitor Kimia Jenis Koktail untuk Proteksi Korosi Baja API 5L Grade B dalam Larutan NaCl 3,5% Rani Kusumawardani; Agus Budiono; Johny Wahyuadi Soedarsono; Yudha Pratesa
Recent in Engineering Science and Technology Vol. 3 No. 3 (2025): RiESTech Vol. 3 No. 3 Years 2025
Publisher : MBI

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.59511/riestech.v3i3.112

Abstract

Method to prevent the corrosion during pipeline hydrotest using seawater is generally by the addition of inorganic inhibitor containing corrosion inhibitor agent, oxygen scavenger and biocide, so that require to find out the alternative eco-friendly materials with better performance. The main objective of this study is to investigate the efficiency of the use of mixture of extract of Myrmecodia pendans and Piper crocatum as an alternative of eco-friendly inhibitor for reducing the use of inorganic inhibitors for corrosion protection of steel material API 5L Grade B in 3.5% NaCl. The corrosion inhibition ability of natural ingredient extraction are investigated by using tafel polarization test and EIS and verified by weight loss test. The content of the active compounds in natural ingredient extraction along with adsorption compound on metal surfaces and inhibition mechanism are investigated by EIS, FTIR and adsorption isotherm model. In the mixed green inhibitor concentration of 2 ml Myrmecodia pendans and 1 ml Piper crocatum is resulted in approximately 73.66% inhibitor efficiency while concentration of 1 ml chemical cocktail and 2 ml green inhibitor are significantly reduce the corrosion rate from 0.42 mm/year to be 0.03 mm/year with approximately 93.15% inhibitor efficiency. The green inhibitor affected the cathodic as well as the anodic polarization curves which were known as mixed corrosion inhibitor type. The adsorption of compounds contained in the Myrmecodia pendans and Piper crocatum on a metal surface are occur spontaneously follows the Langmuir adsorption isotherm.
Assessment of H2S-Induced Cracking Susceptibility in Steam Line Pipes and Weld Zones During Geothermal Well Construction Pragitta, Riene Kaelamanda; Pratesa, Yudha
Journal of Materials Exploration and Findings Vol. 4, No. 1
Publisher : UI Scholars Hub

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Abstract

The susceptibility of steam line pipes, especially in the HAZ (heat-affected zone) and weldment areas, to hydrogen sulfide in the geothermal industry is crucial to understand from the early stages, particularly during construction. The combination of tensile stress from residual stresses after welding and metallurgical phase transformation makes the joint areas vulnerable to sulfide stress cracking. This condition becomes even more extreme when the equipment operates during the well stimulation phase. This research assesses the severity of H₂S-induced cracking using NACE MR0175 and ISO 15156-1 standards, focusing on the effects of pH and partial pressure of H₂S (pH₂S). The findings aim to provide insights into critical factors influencing H₂S cracking susceptibility and to enhance material integrity in geothermal systems. The result shows that while A106 Gr B steel generally meets sour service requirements, certain nodes within the geothermal facility exhibit a moderate risk of cracking under transient conditions. These results emphasize the importance of controlling fluid composition and implementing proper welding procedures to mitigate sulfide stress cracking (SSC).
Co-Authors A. Zakiyuddin AGUS BUDIONO Ahmad Ivan Karayan Aji Wibisono Andika Purnawidhi Badrul Munir Deni Ferdian Fadlilah, Muhammad Iqbal, Adimas Habib Johny Wahyuadi Soedarsono Noviardi, Luthfi Nuringtyas Rahwinarni Pragitta, Riene Kaelamanda Rani Kusumawardani Sri Harjanto Vika Rizkia Wahyuaji Narottama Putra Yunita Sadeli