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"The performance of a quartz crystal microbalance (QCM) biosensor can be enhanced by patterning the surface of the SiO2 substrate. In this study, the patterning was realized by a plasma etching process. The etching of the SiO2 was carried out using a tetrafluoroethane (CH2FCF3) plasma. The plasma was generated by applying power from a generator. The generator used in this research was a low frequency 40 kHz plasma generator. The generator was equipped with automatic matching circuits, which ensured the stability of plasma power during the experiments. The specimens were produced with a power ranging from 40 watts to 120 watts for 1 hour. The pressure of the chamber was fixed at 1 Torr. The processing gas for this study was a commercial CH2FCF3 gas. The flow rate of the gas was 20 ml/min. The purpose of this research was to study the effect of plasma power on the etching rate and the anisotropy of the etched SiO¬2 surface. The etching rate and the anisotropy strongly correlate with the quality of patterning. Measurement and observation of the etched SiO2 surface were carried out using an optical microscope and a TMS-1200 (Topography Measurement System). The optical microscope was used to determine the etched area from the unetched one, while the TMS was utilized to obtain the thickness and the surface profile. The results show the highest etching rate, i.e., 17.90 nm/min, was obtained by applying a plasma power of 100 watts. The rate demonstrated a relatively slow etching process due to a complex mixture of fluorine (F) and the CH2FCF2 compound. This slow etching rate is preferable for controlling nano-profiles of the pattern. Furthermore, the applied power also had an effect on the anisotropy of the etched profile, and the results of this research show that the best anisotropic coefficient, i.e., 4.8×10-2, occurred in the process with an optimized 110-watt power. The anisotropy was defined as the ratio of the vertical etching rate and the horizontal etching rate. This ratio is important in determining the quality of the profile of the patterned QCM."

"Sistem penciuman elektronik atau biasa disebut hidung elektronik, meniru kerja jaringan indra penciuman manusia. Pada keseluruhan sistem penciuman elektronik dapat dibagi menjadi sistem sensor, sistem elektronik, dan sistem pengambil keputusan yang dapat mengenali jenis aroma tertentu. Sistem sensor dapat dikembangkan dengan memanfaatkan efek pembebanan masa pada bidang piezoelectric, dengan memodifikasi suatu kristal kuarsa yang bekerja pada frekuensi tertentu. Perancangan rangkaian resonan yang tepat akan menghasilkan resonansi yang stabil sehigga menunjang performa pembacaan sensor. Diharapkan dengan peningkatan frekuensi kerja dari kristal kuarsa yang digunakan akan menghasilkan kemampuan pengenalan aroma yang lebih baik dari sistem yang telah dibuat pada penelitian sebelumnya.

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Electronic sensing odor or usually know as electronic nose working by imitating how human nose sensing. Complete system of an odor sensing could be divided as sensor system, electrical system, and decision making system. Sensor system could be developded by using mass loading efect at piezoelectric material, it posiby developed by modifiying quartz crystal working at it frequency. Designing correct oscillator circuit is necessery for good reading preformance of the sensor. Better performance of detecting odor, expected by increse quartz crystal frequency from research already done before."

"Penelitian ini telah berhasil melakukan pengujian produksi gas klor menggunakan membran penukar kation dan membran nafion dengan metode elektrolisis plasma. Pengujian ini meliputi pengukuran pH, konduktivitas, produksi gas klor dan konsumsi energi selama proses reaksi berlangsung. Hasil pengujian menunjukkan penggunaan membran penukar kation meningkatkan kemurnian produk NaOH. Produksi gas klor pada membran penukar kation meningkat 4,3 kali dibandingkan dengan membran nafion dan meningkat 1,3 kali dibandingkan dengan tanpa menggunakan membran. Sementara konsumsi energi per mmol produk menurun 3,1 kali dibandingkan dengan membran nafion dan menurun 1,7 kali dibandingkan dengan tanpa menggunakan membran. Hasil pengujian elektrolisis plasma dengan membran penukar kation menunjukkan terjadi peningkatan produksi gas klor sebesar 33,3 kali dibanding proses elektrolisis dengan membran penukar kation. Sementara konsumsi energi per mmol produk menunjukkan penurunan dari 473,64 kJ/mmol pada proses elektrolisis menjadi 25,85 kJ/mmol pada proses elektrolisis plasma.

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This study has successfully tested the production of chlorine gas using a cation-exchange membrane and nafion membrane with plasma electrolysis method. These tests include measurement of pH, conductivity, chlorine gas production and energy consumption during the reaction. The test results showed the use of cation exchange membrane increases NaOH product purity. The production of chlorine gas on the cation exchange membrane increased 4.3 times compared with the nafion membrane and increased 1.3 times compared with no use of membrane. While energy consumption per mmol product decreased 3.1 times compared with the nafion membrane and decreased 1.7 times compared with no use of membranes. The test results of plasma electrolysis with cation exchange membrane showed an increase in the production of chlorine gas by 33.3 times compared with the electrolysis process cation exchange membrane. While energy consumption per mmol of the product showed a decline of 473.64 kJ / mmol in the electrolysis process be 25.85 kJ / mmol on plasma electrolysis process."

"Limbah fenol seringkali mencemari air dan tanah, mengakibatkan pencemaran yang merugikan bagi ekosistem serta menyebabkan risiko serius terhadap kesehatan manusia. Metode elektrolisis plasma adalah salah satu cara efektif untuk menanggulangi masalah limbah ini. Penelitian ini bertujuan untuk menganalisis pengaruh variasi daya pada tegangan tetap, konsentrasi awal limbah, dan penggunaan elektroda stainless steel SS-316 terhadap efektivitas proses yang meliputi fenomena pembentukkan plasma, degradasi limbah fenol, dan ketergerusan anoda. Dalam penelitian ini, udara diinjeksikan melalui katoda menggunakan lengkungan yang akan mengarahkan udara langsung ke zona terbentuknya plasma di anoda. Penelitian dilakukan dengan reaktor 1,2 L menggunakan variasi daya 250 W, 300 W, dan 350 W; dan variasi konsentrasi awal limbah 100 ppm, 200 ppm, dan 300 ppm W dengan elektrolit K2SO4 0,02 M. Pada penelitian ini, didapat hasil degradasi yang lebih baik oleh elektroda stainless steel dibandingkan tungsten. Selama 30 menit, SS-316 mampu mendegradasi fenol hingga 99% sedangkan tungsten hanya mencapai 84%. Sementara itu, ketergerusan tungsten jauh lebih besar dibandingkan SS-316. Pada percobaan ini, hasil degradasi tertinggi mencapai 99,9% yang didapat pada kondisi 350 W, konsentrasi limbah fenol 100 ppm, tegangan 550 V, dan dengan penambahan Fe2+ 20 ppm. Pada kondisi optimum ini juga didapatkan penurunan COD sebesar 85,65% dan terdapat produk samping berupa amonia sebesar 5,25 mmol dan nitrat sebesar 0,34 mmol yang terukur pada menit ke-30.

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Phenolic waste often pollutes the air and soil, resulting in pollution that is detrimental to ecosystems and poses serious risks to human health. The plasma electrolysis method is one effective way to overcome this waste problem. This research aims to determine the effect of power variations at a fixed voltage, initial waste concentration, and the use of SS-316 stainless steel electrodes on the effectiveness of the process which includes plasma formation phenomena, phenol waste degradation, and anode erosion. In this research, air is injected through the cathode using an arch that will direct the air directly to the plasma formation zone at the anode. The research was carried out with a 1.2 L reactor using power variations of 250 W, 300 W, and 350 W; and variations in initial waste concentration of 100 ppm, 200 ppm, and 300 ppm W with 0.02 M K2SO4 electrolyte. In this research, better degradation results were obtained by stainless steel electrodes compared to tungsten. For 30 minutes, SS-316 was able to degrade phenol up to 99% while tungsten only reached 84%. Meanwhile, the abrasiveness of tungsten is much greater than that of SS-316. In this experiment, the highest degradation results reached 99.9% which were obtained under conditions of 350 W, waste phenol concentration of 100 ppm, voltage of 550 V, and with the addition of Fe2+ 20 ppm. Under these optimum conditions, COD was also reduced by 85.65% and there were by-products in the form of ammonia of 5.25 mmol and nitrate of 0.34 mmol as measured at the 30th minute."

"Dalam penelitian ini dilakukan pengujian kondisi operasi pada proses produksi gas klor dengan elektrolisis plasma. Proses elektrolisis plasma dapat menurunkan konsumsi energi hingga 24 kali pada reaktor kompartemen tunggal dan 59 kali pada reaktor kompartemen ganda dibandingkan dengan proses elektrolisis. Pada reaktor dengan kompartemen tunggal, tegangan tinggi dapat menyebabkan arus tinggi sehingga konsumsi energi menjadi tinggi. Produksi gas klor terbaik pada konsentrasi 0,5 M dan tegangan 300 V yaitu sebesar 4,63 mmol selama 15 menit dengan konsumsi energi sebesar 134 kJ/mmol Cl2. Pada reaktor dengan kompartemen ganda, arus lebih rendah pada tegangan yang lebih tinggi karena pengaruh jarak kedua elektroda sehingga resistansi menjadi meningkat. Produksi gas klor terbaik pada konsentrasi 0,5 M dan tegangan 700 V yaitu sebesar 11,25 mmol selama 15 menit dengan konsumsi energi sebesar 16 kJ/mmol Cl2. Penggunaan membran selektif ion dapat menghambat perpindahan muatan dari satu elektroda ke elektroda yang lainnya sehingga plasma tidak terbentuk. Membran selektif dapat memisahkan produk samping NaOH, namun produk samping hasil reaksi ion klor tetap terjadi.

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In this study, the operating condition on chlorine gas production by electrolysis plasma is examined. Plasma electrolysis can decrease the energy consumption up to 24 times in single compartment reactor and can reach up to 59 times in double compartment reactor compared to electrolysis process. In reactor with single compartment, high voltage results high current which then cause high energy consumption. The highest chlorine gas production is at 0.5 M and 300 V which results 4.63 mmol for 15 minutes with 134 kJ/mmol Cl2 energy consumption. Furthermore, in double compartment reactor, current is lower due to its higher distance between two electrodes which makes the higher resistance. The highest chlorine gas production is at 0.5 M and 700 V which results 11.25 mmol for 15 minutes with 16 kJ/mmol Cl2. The use of ion selective membrane can resist the movement of charge from one electrode to other. Ion selective membrane can separate side product of NaOH, but side reaction of chlorine ion still exists."

"ABSTRACTHigh Voltage measurement based on the electro-optic effect of LiTaOa crystal plate has been developed. This crystal was placed between two parallel plates which more like capacitor arrangement. On the first step, this system was capable only to measure the do voltage from 0 to 1 kV, and the ac voltage from 0 to 0.3 kV. But, by enlarging the spaces in between one side at crystal to one of the plate surface, d, the range of measurement was increased up to 4.8 kV, with d =7 mm."

"ABSTRAKAsam klorida dapat dimanfaatkan sebagai larutan yang dapat menghasilkan hidrogen dan klor. Sektor industri yang menghasilkan gas klor adalah industri klor-alkali sedangkan industri menghasilkan gas hidrogen adalah steam reforming dan elektrolisis air. Industri klor dan hidrogen mengonsumsi energi dalam jumlah tinggi. Metode elektrolisis plasma dengan asam klorida dapat meningkatkan produksi gas klor dan hidrogen dengan konsumsi energi yang lebih sedikit. Adanya perbedaan tegangan yang sangat tinggi akan menghasilkan spesi radikal pada kedua elektroda. Tegangan, konsentrasi dan kedalaman sangat mempengaruhi produksi gas yang dihasilkan. Selain itu penambahan gas oksigen dapat meningkatkan produksi gas hidrogen 17 kali, sedangkan untuk gas klor dapat meningkat 6 kali lebih banyak dibandingkan elektrolisis Faraday. Sedangkan tanpa injeksi gelembung udara produksi gas hidrogen meningkat 5 kali sedangkan untuk gas klor tidak dapat terdeteksi. Fenomena pembentukan plasma secara simultan dapat dilakukan dengan kondisi kedalaman elektroda dibuat sama dan minimum. Produksi gas yang dihasilkan pada keadaan simultan tidak lebih banyak dibandingkan gas yang dihasilkan secara parsial pada jumlah energi yang sama.

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ABSTRACTHydrochloric acid can be used as a solution that can produce hydrogen and chlorine. The industrial sector that produces chlorine gas is the chlor-alkali industry, while industry generates hydrogen gas is the steam reforming and electrolysis of water. Industrial chlorine and hydrogen consumed energy in high amounts. Plasma electrolysis with hydrochloric acid can increase the production hydrogen and chlor with less energy consumption. The existence of a very high voltage difference will generate radical species at both electrodes. Applied voltage, concentration of electrolye and depth of anode have important influences on the amount of gas resulted. Addition of oxygen can increase hydrogen gas 17 times much more, and can increase chlor 6 times much more than Faraday electrolysis. While without oxygen, hydrogen gas only 5 times much more, and chlor could not detected. Phenomenon of plasma simultaneously could occur if the depth of anode and cathode alike and minimum. In the equal energy total, the amount of gas in simultan method less than the amount of gas in partial methode."

"Berdasarkan RUPTL 2017-2026, kebutuhan pasokan gas bumi untuk Pusat Pembangkit Listrik milik PLN semakin meningkat dari tahun ke tahun, termasuk untuk Pusat Pembangkit Listrik di Jawa Bagian Timur yang berlokasi di Gresik, Perak, Grati (Pasuruan) dan Madura (Sumenep). Sayangnya peningkatan kebutuhan pasokan gas bumi ini tidak diimbangi dengan ketersediaan pasokan gas pipa dari sumber-sumber gas bumi di sekitar Jawa Timur, sehingga diperlukan tambahan pasokan gas bumi dalam bentuk LNG dari luar area Jawa Timur dan sekitarnya. Pada penelitian ini dilakukan optimasi rantai pasokan gas bumi, dalam bentuk gas pipa dan LNG, sehingga didapatkan biaya penyediaan gas bumi terendah di plant gate Pusat Pembangkit Listrik Gresik, Perak, Grati dan Madura. Untuk pola logistik pasokan LNG disimulasikan menggunakan 2 (dua) skenario pasokan, yaitu tanpa Hub LNG dan dengan menggunakan Hub LNG di Gesik. Dari hasil optimasi yang dilakukan menggunakan aplikasi LINGO didapatkan model rantai pasokan gas yang paling optimal dengan skema distribusi LNG tanpa menggunakan Hub serta menggunakan kapal pengangkut LNG berukuran 35.000 m³, 55.000 m³ dan 65.000 m³. Biaya Penyediaan bahan bakar gas terendah untuk periode 2020-2027 adalah 8.022 Juta US$ dengan rata-rata harga gas di plant gate Pembangkit sebesar 8,50 ^US$/_MMBTU.

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Based on RUPTL 2017-2026, the need of natural gas supply for PLNs Power Station will increase from year to year, including for Power Station in Eastern Java located in Gresik, Perak, Grati (Pasuruan) and Madura (Sumenep). Unfortunately, the increasing demand is not followed by the availability of nearby pipeline gas supply sources, so that additional natural gas supply in the form of LNG from outside the area is needed. In this research, natural gas supply chain, both in the form of pipeline gas and LNG will be optimized, so as to obtain the lowest gas supply plant gate cost at Gresik, Perak, Grati and Madura Power Station. LNG supply logistics scheme it is simulated by using 2 (two) supply scenarios, without LNG Hub scenario and using LNG Hub scenario which located at Gresik.  Based on LINGOs optimization result, the most optimal supply chain model obtained by implementing the without LNG Hub scenario using 35.000 m3, 55.000 m3 dan 65.000 m3 LNG vessels. The lowest fuel gas supply cost during 2020-2027 is 8.022 million US$ with an average plantgate gas price at 8,50 US$/MMBTU."