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Journal : Specta Journal of Technology

Studi Penambahan Inhibitor Organik Ekstrak Daun Bawang Tiwai (Eleutherine americana Merr.) pada Baja API 5L dalam Lingkungan 3,5% NaCl Triana, Yunita; Rinda, Sari Shaimah; Jatmoko, Awali; Sulistijono, Sulistijono
SPECTA Journal of Technology Vol 2 No 3 (2018): SPECTA Journal of Technology
Publisher : LPPM ITK

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (720.448 KB) | DOI: 10.35718/specta.v2i3.11

Abstract

One that can be used as an organic inhibitor is bawang tiwai leaves extract. This study used 3.5% NaCl as corrosive media with inhibitor concentration of bawang tiwai leaves extract from 0 ppm to 500 ppm and immersion time from 10 days up to 30 days. The efficiency of inhibition was measured using a weight loss corrosion test, while the corrosion rate was obtained from polarization measurements. The FTIR test results show that the extract contains flavonoid compounds that act as antioxidants and inhibit corrosion. Inhibitory efficiency achieved up to 95.4545% for the addition of 300 ppm inhibitor and 20 days of immersion time. This inhibitory behavior is also supported by polarization measurements where the lowest corrosion rate of 0.00128 mm/year is obtained at the same concentration and immersion time.
Analyze The Effects of Helical Baffles Angles Variation On Shell Side Heat Transfer Coefficient And Pressure Drop of Shell And Tube Heat Exchange Rahmah, Linta Atina; Sa?adiyah, Devy Setiorini; Sulistijono, Sulistijono
SPECTA Journal of Technology Vol 2 No 1 (2018): SPECTA Journal of Technology
Publisher : LPPM ITK

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35718/specta.v2i1.94

Abstract

E-201-11 is one of the components of heat exchanger which serves to increase the temperature of distillated crude oil before it going into the furnace. The use of segmental baffles on the heat exchanger causes dead zone. The fouling phenomenon that arises from the deposition of the compound content in the service fluid in dead zone can result in leakage of the shell and tube. It affects the performance of heat exchanger and production efficiency. The use of discontinuous helical baffle on the shell side minimizes fouling. Research on the variation of helical baffle angle by using Bell-Delaware method resulted in performance value of heat transfer coefficient and pressure drop on the shell side. Fluid flow behavior on the shell side with helical baffle was analyzed by Computational Fluid Dynamics (CFD). The fluid flow velocity is a factor that affects the value of heat transfer coefficient and pressure drop. Heat exchanger with an angle of 10º have fluid flow velocity of 0,893m/s resulting in the highest heat transfer coefficient and pressure drop value compared to angles of 15º and 20º with values of 585.725W/m²K and 13642.395Pa. The heat exchanger with helical baffle at 10° helix angle presents the best performance among the others variant helical baffles
Design of Demodulation Circuit And Arduino Uno Microcontroller Syncronization For Capacitance Sensor Menasita, Menasita; Mirnawati, Mirnawati; Sulistijono, Sulistijono
SPECTA Journal of Technology Vol 3 No 1 (2019): SPECTA Journal of Technology
Publisher : LPPM ITK

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35718/specta.v3i1.114

Abstract

An AC signal is produced by oscillator or a similar circuit that includes demodulation. In addition to thedemodulation circuit, there is also need interface circuit which include signal conditioning, signal processing anddata acquisition. So that, the frequency can be read digitally. The purpose of this research was to createdemodulation circuit in form of colpitts-crystal oscillator and microcontroller. This research carried out severalstage. There are making colpitts-crystal oscillator, microcontroller synchronization, data retrieval and processingoutput. The DC voltage variations are 3.2 V, 9 V and 15.9 V and capacitor variations are 470 pF, 4.7 nF and 33nF. Output data in form of frequencies measured by using oscilloscope. Futhermore, the data is tested for accuracyand precision. From the test result using 470 pF, 4.7 nF and 33 nF capacitors when given 3.2 V input voltage, theprecision values were 91.35%, 93.06% and 96.17% and the accuracy value were 97.72%, 97.96%, and 98.17%.For 9 V input voltage, the precision values were 99.82%, 97.67% and 97.52% and the accuracy value were 99%,98.90%, and 98.92%. Whereas 15.9 V input voltage, the precision values were 93.43%, 96.92% and 93.66% andthe accuracy value were 98.08%, 98.75%, and 97.60%. From these data, it can be concluded that a good voltagevalue used in this ciecuit is 9 V with 470 pF capacitor where the precision value was 99.82% and the accuracyvalue was 99%.
Design of Demodulation Circuit And Arduino Uno Microcontroller Syncronization For Capacitance Sensor Menasita Menasita; Mirnawati Mirnawati; Sulistijono Sulistijono
SPECTA Journal of Technology Vol. 3 No. 1 (2019): SPECTA Journal of Technology
Publisher : LPPM ITK

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (779.963 KB) | DOI: 10.35718/specta.v3i1.114

Abstract

An AC signal is produced by oscillator or a similar circuit that includes demodulation. In addition to thedemodulation circuit, there is also need interface circuit which include signal conditioning, signal processing anddata acquisition. So that, the frequency can be read digitally. The purpose of this research was to createdemodulation circuit in form of colpitts-crystal oscillator and microcontroller. This research carried out severalstage. There are making colpitts-crystal oscillator, microcontroller synchronization, data retrieval and processingoutput. The DC voltage variations are 3.2 V, 9 V and 15.9 V and capacitor variations are 470 pF, 4.7 nF and 33nF. Output data in form of frequencies measured by using oscilloscope. Futhermore, the data is tested for accuracyand precision. From the test result using 470 pF, 4.7 nF and 33 nF capacitors when given 3.2 V input voltage, theprecision values were 91.35%, 93.06% and 96.17% and the accuracy value were 97.72%, 97.96%, and 98.17%.For 9 V input voltage, the precision values were 99.82%, 97.67% and 97.52% and the accuracy value were 99%,98.90%, and 98.92%. Whereas 15.9 V input voltage, the precision values were 93.43%, 96.92% and 93.66% andthe accuracy value were 98.08%, 98.75%, and 97.60%. From these data, it can be concluded that a good voltagevalue used in this ciecuit is 9 V with 470 pF capacitor where the precision value was 99.82% and the accuracyvalue was 99%.