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STUDI DAN KARAKTERISASI LAJU KOROSI LOGAM ALUMINIUM DENGAN PELAPISAN MEMBRAN SOL-GEL Budi Utomo, Rohadi Satrio; Alva, Sagir
Jurnal Teknik Mesin Vol 6, No 3 (2017)
Publisher : Universitas Mercu Buana

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22441/jtm.v6i3.1969

Abstract

Dari beberapa logam seperti baja, tembaga, seng, aluminium dan paduannya, maka aluminium memiliki keunggulan, terutama dalam hal ketahanan terhadap korosi. Ketahanan korosi yang sangat baik oleh aluminium disebabkan oleh adanya lapisan oksida tipis yang menempel sangat kuat di permukaannya (Al2O3). Lapisan Al2O3 stabil pada lingkungan pH 4 s/d pH 9 (pasifasi) sehingga lapisan tersebut dapat melindungi logam bagian dalam dari serangan korosi lanjutan, namun aluminium dapat juga terkorosi dalam lingkungan yang agresif yaitu di luar kisaran pH tersebut terutama suasana asam maupun basa. Hal ini dapat diatasi dengan memberikan coating berupa cat logam terhadap aluminium. Akan tetapi pemberian cat logam tidak dapat dilakukan pada situasi tertentu yang mengharuskan adanya reaksi antara logam dengan lingkungan asam ataupun basa dengan tetap mempertimbangkan ketahan korosi material tersebut, seperti yang terjadi pada baterai. Ini dikarenakan sifat cat yang membendung reaksi antara logam dengan lingkungannya. Oleh karena itu diperlukan penambahan inhibitor korosi dengan mempertimbangkan faktor di atas, yaitu dengan pelapisan membran Sol-Gel. Dari hasil pengujian Sol-Gel yang dilapisi pada aluminium mampu menahan laju korosi pada larutan HCl sebesar 24,26% dan larutan Asam Asetat sebesar 25,57% dibandingkan aluminium tanpa pelapisan. Kemudian membran Sol-Gel juga membuat lapisan pelindung laju korosi yang memiliki pori-pori dengan lebar celah ± 0,56 – 1,12 µm pada pengujian dengan larutan HCl dan ± 0,47 – 1,41 µm pada pengujian dengan larutan Asam Asetat sebagai jalan terjadinya reaksi antara logam dan cairan asam atau basa.
Ag/AgCl Reference Electrode Based on Thin Film of Arabic Gum Membrane Alva, Sagir; binti Abdul Aziz, Aiman Sajidah; bin Syono, Mohd Ismahadi; bin Wan Jamil, Wan Adil
Indonesian Journal of Chemistry Vol 18, No 3 (2018)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (487.528 KB) | DOI: 10.22146/ijc.28859

Abstract

The Ag/AgCl reference electrode based on the Arabic Gum (AG) hydrogel films was successfully developed. The Arabic Gum concentration used in this study was 10–40% (w/v) with an optimum concentration of 20% (w/v). In this study, reference electrode performance testing is based on DmV response of Cl-ion’s measurements, stability tests and performance testing against ISE sensors such as K+, NH4+, and NO3-. The Ag/AgCl based reference electrode of the Arabic Gum film shows an average DmV of 4.0 ± 0.7 mV when response test is performed against a standard Ag/AgCl double junction electrode in various concentrations of Cl-ion’s. Meanwhile, in stability testing conducted in a 0.01 M KCl solution for 72 h found drift of < 0.6 mV/h. The reference performance test of the Arabic Gum reference electrode with three types of ISE NH4+, K+ and NO3- commercial sensors obtaining a slope closer to the Nernst value is 54.9 ± 0.9, 52.3 ± 0.5 and -53.2 ± 0.2 mV/dec with all having a linear distance of 0.1–10-5 M.
CLOSED-HORIZONTAL ROTATING BURNER DEVELOPMENT FOR OPTIMIZING PLAM SHELL CHARCOAL (PSC) PRODUCTION Feriyanto, Dafit; Zakaria, Supaat; Alva, Sagir; Pranoto, Hadi; Sudarma, Andi Firdaus; Wong, Albert Phak Jie
International Journal of Advanced Technology in Mechanical, Mechatronics and Materials Vol 1, No 2 (2020)
Publisher : Institute for Research on Innovation and Industrial System (IRIS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (514.355 KB) | DOI: 10.37869/ijatec.v1i2.23

Abstract

Activated Carbon (AC) was produced through several stages such as carbonization, crushing and activation process. The critical part of AC production was located at carbonization process due to burner issues that need to complete burning in short time, appropriate temperature and low cost. Therefore, this research focus on developing burner which called by closed-horizontal rotating burner. The dimension of the burner was 65 x 790 mm (D x L) wih the capacity of 30 kg/carbonization process. This burner need 1 hour for complete burning of palm shell to palm shell charcoal (PSC). Several analysis were conducted such as stress, displacement, factor of safety and thermal analysis. because this burner involved in rotation motion and high temperature operation. Physical properties has been measured which consists of moisture content (3.8-5%), ash content (7.7-8%), volatile content (53.7-56.6%) and fixed carbon content (31.3-34.7%). It can be summarized that this burner was very effective to produce PSC with short time carbonization process, low cost and complete charcoal production.
Preliminary Study of Poly(Tetrahydrofurfuryl Acrylate) Thin Film As a Potential Material of Ion Selective Electrodes: The Case of Nitrate Ion-Selective Electrode Alva, Sagir
Indonesian Journal of Chemistry ARTICLE IN PRESS
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (18.17 KB) | DOI: 10.22146/ijc.44478

Abstract

A preliminary study of the use of a poly-tetrahydrofurfuryl acrylate (pTHFA) synthesized by photopolymer techniques has been successfully performed as an alternative membrane for the fabrication of the ISE sensors such as a Nitrate-ISE. The membrane of the pTHFA photopolymers is optimized by varying the concentration of the photo-initiator with five variations. The results of the photo-polymer were characterized using C-NMR, H-NMR FTIR and DSC. The result that obtained the composition I as the best material to be applied with value Tg -17.3oC. In the fabrication process of the Nitrare-ISE, optimization of the tetraoctylammonium nitrate immobilization process (TOAN) into a mixture of the composition I was performed. The optimum concentration of the TOAN was 4.2 mg. This is seen from the results of the ISE sensor performance testing nitrate that has a slope near the Nersntian number with linear range 0.1- 10-4 M and LOD of 3.47 x 10-5 M. The performance test is also done by a selectivity coefficient test using SO42-, H2PO4-, HPO42, Cl- and I- ions as interfering ions. The results of the selectivity coefficient test are -2.27 ± 0.2, -2.49 ± 0.6, -2.18 ± 0.8, -1.31 ± 0.1 and 0.41 ± 0.2, respectively. ISE-Nitrate sensor developed also shows the results that are comparable to the standard method to measurement of real samples such as fish ponds, soils and also rivers.
Analisis Potensi Limbah Logam/Kaleng, Studi Kasus di Keluarahan Meruya Selatan, Jakarta Barat Anggraini, Rini; Alva, Sagir; Yuliarty, Popy; Kurniawan, Teddy
Jurnal Teknik Mesin Vol 7, No 2 (2018)
Publisher : Universitas Mercu Buana

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22441/jtm.v7i2.3022

Abstract

          Sampah atau limbah padat  merupakan material sisa yang dapat memberikan dampak negative karena dapat merusak lingkungan, tetapi juga dapat memberikan dampak positif apabila dikelola dengan teknik tertentu. Limbah logam merupakan limbah yang mudah dipisahkan dari timbunan sampah dan dapat didaur ulang menjadi barang – barang yang bernilai seni, dilebur kembali sebagai menjadi material asalnya, dan juga dapat dimanfaatkan sebagai campuran semen dan sebagainya.Penelitian ini bertujuan untuk mengetahui potensi limbah logam yang ada di Kelurahan Meruya Selatan Jakarta Barat. Penelitian dilakukan dengan melakukan observasi ke lokasi penelitian, melakukan wawancara dengan pihak-pihak yang terkait dengan penelitian dan dengan menyebarkan kuesioner. Sedangkan untuk mengetahui potensi limbah logam di wilayah penelitian, menggunakan analisa  teknik analisa data berkala.             Hasil penelitian  menunjukkan bahwa jumlah limbah logam yang terkumpul di Bank Sampah RW 4 dan RW 9 Kelurahan Meruya Selatan menunjukkan kenaikan selama tahun 2016 dan 2017, meskipun dari segi kuantitas jumlahnya kecil. Hasil analisa trend untuk limbah besi adalah Y  =    -  2,005 +  0,69X, untuk limbah aluminium Y  = -  0,6765  +  0,183X  , untuk limbah kaleng Y  =   2,0169   +  0,0042X  , dan untuk total limbah logam Y  =  - 0,71   +  0,0042X. Dimana Y merupakan variabel jumlah limbah dan X merupakan variabel waktu.