Judul: Simulasi Perancangan Sel Surya Multijunction Al0.3Ga0.7As/GaAs/Ge Menggunakan Program PC1D Dan Matlab
Abstrak: Solar cell design is based on the composing of semiconductor layers (multijunction) with energy gap varies in each layer are arranged from highest to lowest can maximize the absorption of solar radiation intensity. Using optimum doping and optimum thickness on semiconductor can maximize the power conversion of the intensity absorbed. Absorbed intensity and amount of electrical power generated at each layer can increase the total efficiency of solar cell. Simulations carried out with 2 models, model 1 which produce different currents and model 2 that produce the same current. Semiconductor layers used is Al0.3Ga0.7As, GaAs, and Ge. Model 1 produces currents Isc at each layer of 26.4 mA, 14.9 mA, and 13 mA and total efficiency of 39.2%. Model 2 produces constant currents of 13 mA and total efficiency of 21.7%. The entire simulations were performed using 0.1367 W/cm2 of solar intensity that obtained from calculation of black body radiation spectrum of the sun's surface at 6000K
Keyword: 

Judul: Simulasi Perancangan Sel Surya Triple Junction Al0.3Ga0.7As / InP / Ge Menggunakan Program PC1D Dan Matlab
Abstrak: Solar cells are one source of renewable energy that harnesses sunlight for generating electricity. Increasing the efficiency of solar cells can be done by preparing a multiple layer of semiconductors with different energy gap, commonly referred to as multijunctions solar cells. Simulations were carried out in two different models. Model 1 is a simulation that generate different valuer of currents in each layer. while Model 2 is a simulation that generate the same value currents in each layer. In Model 1, those three layers of Al0.3Ga0.7As / InP / Ge produce 26.2 mA, 16.2 mA, and 11.0 mA of ISC current respectively. The total efficiency for this model is 38.86 %. As for simulation of Model 2 Isc current value is fixed for each layer is 11.9 mA. The total efficiency of Model 2 is obtained around 20.26 %. All simulations is performed using Solar Irradiance of 1367 W/m2 obtained from the calculation of the blackbody radiation spectrum, at 6000 K.
Keyword: 

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.
Keyword: