Judul: Efek Modifikasi π-Spacer dan Akseptor terhadap Sifat Elektronik dan Optik Galangin sebagai Zat Pemeka Sel Surya
Abstrak: Energi matahari menjadi sumber energi listrik alternatif yang dapat dipanen menggunakan Dye Sensitized Solar Cells (DSSC). Eksplorasi sifat elektronik dan optik pewarna menjadi penting mengingat performansi DSSC bergantung juga pada performansi pewarna yang digunakan. Perbaikan performansi pewarna dapat dilakukan dengan memodifikasi strukturnya. Studi ini mengeksplorasi performansi galangin termodifikasi secara komputasi menggunakan DFT dengan level teori B3LYP dan basis set def2-SVP. Modifikasi dilakukan dengan memvariasikan tiofena dan furan sebagai π-spacer serta 4-etinil asam benzoat dan asam sianoasetat sebagai akseptor. Molekul dengan tiofena dan asam sianoasetat memiliki performansi paling baik ditinjau dari sifat elektroniknya. Sifat optiknya yang kurang optimal diatasi dengan memvariasikan jumlah gugus π-spacer yang digunakan. Molekul dengan 2 gugus tiofena memberikan performansi yang lebih baik lagi. Hal ini berkaitan dengan efektivitas delokalisasi elektron π pada tiofena dan kemampuan penarikan elektron yang dimiliki asam sianoasetat. Molekul ini sudah sangat layak untuk diterapkan sebagai pewarna, karena karakteristik elektronik dan optiknya sudah baik., Solar energy is an alternative source of electrical energy that can be harvested using Dye-Sensitized Solar Cells (DSSC). Exploration of the electronic and optical properties of dyes is important because performance of DSSCs also depends on the dye’s performance. Performance of dye can be improved by modifying its structure. This study computationally explores the performance of modified galangin using DFT with B3LYP theory level and def2-SVP basis set. Modifications were made by varying thiophene and furan as π-spacers also 4-ethynyl benzoic acid and cyanoacetic acid as acceptors. Molecule with thiophene and cyanoacetic acid has the best performance in terms of their electronic properties. Its optical properties were overcomed by varying the number of π-spacer groups used. Molecules with 2 thiophene groups give even better performance. This is related to the effectiveness of π-electron delocalization in thiophene and the electron-withdrawing ability of cyanoacetic acid. This molecule is very feasible to be applied as a dye, because its electronic and optical characteristics are very good.
Keyword: absorption spectra, DFT, DSSC, energy gap, galangin

Judul: Performance of Dye Sensitized Solar Cell Based on Sulfonated Polystyrene and Natural Dye Butterfly Pea Flower
Abstrak: Dye Sensitized Solar Cell (DSSC) adalah seperangkat sel surya yang berbasis fotoelektrokomia yang melibatkan transfer muatan listrik dari suatu fase ke fase lain Pewarna yang digunakan pada penelitian ini adalah sari alami bunga telang yang didapatkan dari proses tanpa maserasi. DSSC terdiri atas elektrode kerja, pewarna, dan elektrode lawan. Larutan elektrolit yang umum digunakan adalah I- /I3 - namun elektrolit ini mempunyai kelemahan mudah menguap sehingga dapat menurunkan nilai efisiensi DSSC. Penelitian ini bertujuan mengetahui penggunaan sari alami bunga telang sebagai zat warna pada sistem DSSC, pengaruh penambahan polistirena tersulfonasi disebabkan potensinya sebagai elektrolit DSSC dengan dua perlakuan berbeda yaitu pencampuran dan perendaman pewarna terhadap TiO2 yang memengaruhi nilai efisiensi kinerja DSSC. Nilai efisiensi DSSC dengan perlakuan pencampuran dan penambahan PSS menghasilkan efisiensi tertinggi sebesar 1,56%. Teknik pewarnaan terhadap PSS melalui proses pencampuran memperoleh efisiensi kinerja lebih baik dibandingkan dengan proses perendaman., Dye Sensitized Solar Cell (DSSC) is a set of solar cells based on photoelectrochemistry which involves the transfer of electrical charge from one phase to another. The dye used in this research is the natural essence of butterfly pea flowers obtained from a process without maceration. DSSC consists of a working electrode, dye, and counter electrode. The electrolyte solution that is commonly used is I- /I3 - , but this electrolyte has the weakness of being volatile so that it can reduce the efficiency value DSSC. This study aims to determine the use of natural butterfly pea flower as dyes in the DSSC system, the effect of adding sulfonated polystyrene due to its potential as a DSSC electrolyte with two different treatments, namely mixing and soaking dyes against TiO2 which affects the efficiency value of DSSC performance. The efficiency value of DSSC with PSS mixing and addition treatment resulted in the highest efficiency of 1.56%. The staining technique for PSS through the mixing process obtained better performance efficiency compared to the soaking process.
Keyword: bunga telang, DSSC, efisiensi, polistirena tersulfonasi

Judul: Posisi Filogenetik Kura-Kura Carettochelys Insculpta  (Reptillia: Testudinata)
Abstrak: Carettochelys insculpta is an endemic freshwater turtle of southern Papua and northern Australia. Phylogenetic position of this turtle is remain unresolved until now. Most of the research conducted show close relationships of C. insculpta and members of Trionychidae family. However, some of the research show distance between C. insculpta and members of Trionychidae family. This research is conducted to analyze phylogenetic relationship between C. insculpta and other members of Testudinata using 12S rRNA, 16S rRNA, and both gene as markers. DNA samples were obtained from three different organisms of C. insculpta. Two species used as outgroups were Alligator mississippiensis and Iguana iguana. Phylogenetic analysis was carried out using Neighbor-Joining method with Felsenstein 1981 (F81) modeltest. A polytomy tree of Testudinata was produced by using 12S rRNA gene. However, analysis using 16S rRNA and both genes as markers confirmed that C. insculpta was located between the Chelonidae and the Trionychidae family.
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