Judul: Pengaruh Multiplikasi Spektrum AM1.5G terhadap Nilai Efisiensi Sel Surya Multijunction Al0.3Ga0.7As/InP/Ge
Abstrak: Sel surya merupakan teknologi alternatif yang mengkonversi energi matahari menjadi energi listrik. Akan tetapi, efisiensi yang dihasilkan oleh sel surya pada umumnya masih kecil. Peningkatan efisiensi sel surya dapat dilakukan dengan cara menyusun beberapa semikonduktor yang memiliki energi gap berbeda atau biasa disebut dengan istilah multijunction. Efisiensi yang tinggi mampu dihasilkan oleh sel surya multijunction dengan meningkatkan intensitas radiasi yang datang. Pada penelitian ini telah dilakukan pemodelan sel surya multijunction dengan material Al0.3Ga0.7As/InP/Ge mempergunakan program PC1Dv5.9 dan Matlab R2010a. Pemodelan ini mempergunakan AM1.5 G sebagai spektrum masukan dengan variasi konsentrasi masukan 1 sun, 5 suns, 10 suns dan 100 suns, 200 suns. Efisiensi total multijunction Al0.3Ga0.7As/InP/Ge meningkat seiring dengan bertambahnya konsentrasi masukan bahan. Efisiensi bahan meningkat hingga 79% pada konsentrasi 100 suns. Kenaikan intensitas yang terlalu tinggi akan menurunkan efisiensi dari bahan sehingga parameter-parameter lain harus diperhatikan ketika meningkatkan konsentrasi sinar matahari yang datang.
Keyword: Efisiensi, multijunction, sel surya, spektrum AM1.5G

Judul: Simulasi Kinerja Sel Surya 4-Junction Al0.3Ga0.7As/GaAs/InP/Ge dengan Pembatasan Daerah Serapan Radiasi Matahari.
Abstrak: Solar cells development increased rapidly indicated by the increasing solar cells efficiency. One way to increase the efficiency is by using multi-junction solar cells. In this research, 4-junction solar cells Al0.3Ga0.7As/GaAs/InP/Ge has been designed and simulated using PC1Dv5.9 program in two different models. In Model 1, different current is produced in each sublayer, while in Model 2 the identical current restricted in each sublayer. Every models are simulated in two different conditions, i.e without absorption area restriction (wavelength fron 280 to 2500 nm) and with restriction of solar radiation (restricted cutoff wavelength). Model 1 showed that solar cells without spectrum restriction (efficiency 64.23%) are more efficient than the one with restriction (efficiency 36.48%). Model 2 showed smaller efficiency compared to Model 1, with 12.75 % efficiency for solar cells without spectrum restriction and 2.81% for the one with restriction. All simulations were performed using AM1.5G radiation spectrum.
Keyword: solar cells, PC1D program, multi-junction, efficiency

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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