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"Three types of antimony and bismuth electrolytic cells to be used for lead electrorefining were developed and tested. The electrolytic cell with the bipolar metallic electrode, the electrolytic cell with two anodes and one cathode, and the electrolytic cell with the porous diaphragm were studied. The tests demonstrated that lead is effectively separated from the metallic impurities in all constructions. Grade lead may be obtained at the cathode, and lead-antimony and lead-bismuth alloys may be produced at the anode. The electrolytic cell with a porous diaphragm was found to double the production rate and greatly decrease the electrical potential of the cell as compared to the other two constructions."

"Plasma electrolytic oxidation (PEO) merupakan metode rekayasa permukaan logam untuk menghasilkan lapisan oksida yang keras dan tahan korosi. Sifat lapisan oksida yang dihasilkan bergantung pada jenis substrat dan komposisi larutan yang digunakan. Dalam penelitian ini, PEO dilakukan pada substrat AZ31B pada kondisi rapat arus tetap 800 A/m2 dan suhu 30°C. Larutan terdiri atas campuran garam basa dan etanol. Larutan A terdiri atas campuran 0,5 M Na3PO4 dan etanol dengan komposisi 9:1, larutan B campuran Na3PO4, NaOH dan Na2CO3 dengan komposisi 8:1:1, larutan C, D, dan E campuran Na3PO4, NaOH, Na2CO3, dan etanol dengan komposisi 7:1:1:1, 6:1:2:1, dan 6:2:1:1. Morfologi dan komposisi lapisan oksida diamati dengan scanning electron microscope dan energy dispersive spectroscopy (SEM – EDS). Komposisi kristal dianalisis dengan x-ray diffraction (XRD). Nilai kekerasan mekanik diuji dengan mesin microVickers Hardness. Perilaku korosi sampel diuji dengan metode electrochemical impedance spectroscopy (EIS) dan potentiodynamic polarization (PDP). Etanol di dalam larutan tidak mempengaruhi morfologi dan komposisi coating. Semua coating memiliki kandungan fasa kristal Mg3(PO4)2 pada puncak 29° hingga 35°. Nilai kekerasan coating yang terbentuk di larutan A, B, C, D, dan E adalah 451,8; 388; 237; 156,8; 158,4 HV. Nilai kekerasan yang rendah pada coating C, D, dan E disebabkan oleh rendahnya konsentrasi Na3PO4 yang menurunkan populasi plasma selama proses coating. Selain itu, kehadiran ion karbonat di dalam larutan mentriger peningkatan pori di dalam coating. Hasil uji polarisasi menunjukkan peningkatan ketahanan korosi dua orde dibanding substrat. Penambahan etanol ke dalam larutan cenderung menurunkan sedikit ketahanan korosi coating.

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Plasma Electrolytic Oxidation (PEO) is a method of engineering metal surface treatment to produce a hard and corrosion-resistant oxide layer. The result properties of oxide layer depend on type of substrate and composition solution was used. PEO process is carried out a constant current 800 A/m2 at temperature 30℃. The solution composed of mixture alkaline salts and ethanol. Solution A mixture of 0,5 M Na3PO4 and ethanol with composition of 9:1, solution B a mixture Na3PO4, NaOH and Na2CO3 with composition of 8:1:1, solution C, D, and E a mixture of Na3PO4, NaOH and Na2CO3 with ethanol with composition of 7:1:1:1; 6:1:2:1; and 6:2:1:1. Morphology and composition of the oxide layer were observed by scanning electron microscope and energy dispersive spectroscopy (SEM – EDS). The crystal composition was analyzed by x-ray diffraction (XRD). The value of mechanical hardness was tested with a microVickers Hardness machine. The corrosion behavior of the samples was tested by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP) methods. The presence of ethanol in the solution didn’t affect morphology and composition of coating. All coatings contain Mg3(PO4)2 crystal phase at peak 29° to 35°. The hardness value of coating formed in solution A, B, C, D and E is 451.8; 388; 237; 156.8; 158.4 HV. The low hardness values in coatings C, D, and E were caused by the low concentration of Na3PO4 which reduced plasma population during the coating process. In addition, the presence of carbonate ions in the solution triggers an increase in the pores in the coating. The results of the polarization test showed can increase corrosion resistance of two orders compared to substrate. Addition of ethanol to solution tends to slightly lower the corrosion resistance of coating."

"ABSTRACTSel surya perovskite kini telah mencapai efisiensi senilai 23,3% yang beranjak dari 3,8% hanya dalam jangka waktu beberapa tahun. Material utama yang digunakan pada sel surya perovskite merupakan material dengan struktur perovskite sebagai lapisan aktif dari sel tersebut, seperti contohnya, methylammonium lead halide (CH3NH3PbI3). Material perovskite CH3NH3PbI3 ini menggunakan senyawa inorganik timbal klorida (PbCl2), dimana senyawa tersebut memiliki toksisitas yang tinggi dan dapat menyebabkan gangguan kesehatan, seperti kerusakan sistem saraf, otak, kanker, dan lainnya. Berbagai penelitian telah menunjukkan secara lebih lanjut bagaimana pengaruh timbal klorida terhadap kesehatan. Namun, belum ada penelitian yang secara langsung membahas mengenai bagaimana pengaruh jumlah kandungan PbCl2 terhadap karakteristik elektris sel surya perovskite CH3NH3PbI3. Pada skripsi ini dibahas mengenai pengaruh jumlah kandungan PbCl2 terhadap karakteristik elektris sel surya perovskite CH3NH3PbI3. Pada skripsi ini pula, difabrikasikan tiga sel surya pervoskite dengan lapisan aktif perovskite yang memiliki jumlah kandungan PbCl2 yang berbeda, yaitu 120 mg, 130 mg, dan 140 mg. Dari fabrikasi yang dilakukan, diperoleh hasil bahwa peningkatan jumlah kandungan PbCl2 membuat sel surya CH3NH3PbI3 memiliki karakteristik elektris yang lebih baik. Sel dengan performa terbaik pada penelitian ini adalah sel dengan140 mg PbCl2, dengan nilai Voc = 0,879 V;

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ABSTRACTIsc =3,3 mA, FF = 0,47 dan η = 0,88%. Perovskite solar cells has reached 23.3% from 3.8% efficiency only in a few years range. The main material that used in perovskite solar cells are materials with perovskite structure as an active layer of those cells, such as methylammonium lead halide (CH3NH3PbI3). CH3NH3PbI3 perovskite contains inorganic compound lead chloride (PbCl2), which has high toxicity that can cause health hazards, such as damage to nervous systems, brain, cancer, etc. Many researches has shown further how the influence of lead chloride on health. However, there are currently no research that directly discusses about the effect of the amount of PbCl2 content on the electrical characteristics of CH3NH3PbI3 perovskite solar cell. This research discusses the effect of the amount of lead chloride on the electrical characteristics of perovskite solar cell. Three perovskite solar cells were fabricated in this research which the active perovskite layer has varying amounts of PbCl2 content, namely 120 mg, 130 mg, and 140 mg. The results of the fabricated cells shows that the increase in the amount of PbCl2 content makes the CH3NH3PbI3 solar cells have better electrical characteristics. Cell with the best performance in this research is the cell with 140 mg amounts of PbCl2 content, with the value Voc = 0,879 V, Isc = 3,3 mA, FF=0,47, and η=0,88%."