Judul: DFT Study on the Effect of In Vacancy-Point Defect and Ag+ Doping on Properties of Cs2ScInCl6 Double Perovskite as Solar Cell Candidate
Abstrak: Perkembangan konsumsi energi global yang terus meningkat mendorong pemanfaatan sumber energi terbarukan seperti energi matahari dalam transformasi menjadi energi listrik, seperti teknologi fotovoltaik dinamakan sel surya. Pemanenan energi surya dengan teknologi ini dapat menggunakan Double Perovskite (DP) sebagai material yang dapat menyerupai kinerja perovskit berbasis timbal (Pb). Akibat Pb yang memiliki permasalahan dari sisi toksisitasnya, kemudian dilakukan uji DP Cs2ScInCl6 dengan mengeksplorasi sifat elektronik dan optiknya secara komputasi menggunakan DFT. Selain itu, untuk mendapat perbaikan performansi dapat dilakukan dengan memodifikasi strukturnya berupa pengadaan vacancy-point defect (x = 0,25) dan kombinasi vacancy-point defect dan doping ion Ag+ serta variasi metode Spin Orbit Coupling (SOC) dan tanpa SOC. Cs2ScIn1-0,25Cl6 tanpa SOC memiliki performansi yang baik ditinjau dari sifat elektroniknya. Sedangkan ditinjau dari keseluruhan terlepas dari transisinya Cs2ScIn1-0,25Ag0,25Cl6 tanpa SOC memberikan performansi paling baik sebagai kandidat sel surya DP Cs2ScInCl6 dilihat dari gap-nya yang berkaitan dengan kemampuan absorbsi foton dengan spektrum yang lebar., The development of global energy consumption that continues to increase encourages the use of renewable energy sources such as solar energy in the transformation into electrical energy, such as photovoltaic technology called solar cells. Solar energy harvesting with this technology can use Double Perovskite (DP) as a material that can resemble the performance of lead-based perovskite (Pb). As a result of Pb which has problems in terms of toxicity, then the DP Cs2ScInCl6 test was carried out by exploring its electronic and optical properties computationally using DFT. In addition, to get improved performance can be done by modifying the structure in the form of procurement vacancy-point defect (x = 0,25) and a combination of vacancy-point defect and doping ion Ag+ and variations of Spin Orbit Coupling (SOC) and no SOC methods. Cs2ScIn1-0,25Cl6 without SOC has good performance in terms of its electronic properties. While in terms of overall regardless of the transition Cs2ScIn1-0,25Ag0,25Cl6 without SOC gives the best performance as a candidate DP solar cell Cs2ScInCl6 seen from itsgap related to the absorption ability of photons with a wide spectrum.
Keyword: Bandgap, DFT, Double Perovskite, Transition, Vacancy-Point

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: Bakteri Flora Paling Umum Ditemukan Di Rongga Mulut Python Retikulatus Liar
Abstrak: Reticulated python is a non-venomous snake native to South and Southeast Asia. It is the world's longest snake. The purpose of this literature review study is to investigate the common bacterial flora found in oral cavity of the reticulated python. The data for this case study was obtained from several articles, journals, books and credible websites. Based on existing data, there are a wide variety of bacteria in the oral cavity of free-living reticulated pythons. The majority of the organisms were Gram-negative. Pseudomonas spp. were the most commonly isolated bacterial species, being found in 50% of the snakes sampled, and was followed by Staphylococcus sciuri.
Keyword: Reticulated python, snake bites, bacterial flora, oral cavity, microbiology