Judul: Rancang Bangun Karburator Uap untuk Motor Bakar Bensin.
Abstrak: Bensin merupakan bahan bakar yang paling banyak digunakan saat ini dan merupakan salah satu bentuk olahan dari minyak bumi yang tak terbarukan. Cadangan minyak bumi semakin menipis dan suatu saat akan habis. Bensin paling banyak digunakan untuk motor bakar dan memerlukan peningkatan efisiensi dalam konsumsinya. Tujuan penelitian ini adalah untuk meningkatkan efisiensi konsumsi bensin yang digunakan oleh motor bakar dengan merancang dan mengaplikasikan karburator uap. Rancangan karburator uap menggunakan ruang penguap bensin yang terhubung dengan pipa inlet, pipa outlet dan flange-nya, katup throttle, katup udara, dan sistem pelampung. Karburator uap ini bekerja dengan cara menguapkan bensin dan mencampurkannya dengan udara sebelum masuk ke dalam ruang bakar didalam motor bakar. Kinerja karburator uap diuji menggunakan motor bakar Honda GX120, yang terhubung dengan generator dan beban listrik. Kinerja karburator uap diuji dan dibandingkan dengan karburator standar menggunakan tiga beban berbeda, yaitu 1200 W, 850 W, dan 600 W. Pengujian sesuai urutan beban tersebut menghasilkan nilai konsumsi bensin karburator uap 55,5%, 46,7%, dan 69,3% lebih rendah daripada karburator standar. Nilai SFC karburator uap 54,1%, 46,9%, dan 68,7 % lebih rendah dan nilai efisiensi konversi bahan bakar 120,54% , 89,22%, dan 214,79% lebih tinggi daripada karburator standar.
Keyword: efisiensi, karburator, karburator uap, motor bakar

Judul: Penerapan Bahan Bakar Biogas pada Motor Bensin dengan Modifikasi Karburator dan Variasi Rasio Kompresi
Abstrak: Biogas is one of the gaseous bio-energy can be applied into gasoline motors with some modification of components. The objectives of this research are applying the biogas fuel in gasoline engine with carburetor modification, measuring and getting value of maximum power and maximum torque and minimum value of the specific fuel consumption of each variation of compression ratio. The results of research were the biogas fuel on gasoline motors could be implemented directly, carburetor modifications changed the ratio of air and fuel ratio of 14.7: 1 (gasoline) to 5.7:1 (biogas) as of gasoline engine could be operated with engine speed over 1500 rpm up to 4500 rpm in a stable condition. The maximal power values for each compression ratio were 0.827 kW at compression ratio (CR 7.6), 0.953 kW (CR 8.3), 0.838 kW (CR 9.0) and 0.764 kW (CR 10.0). Maximum torque values were 3.071 N.m at compression ratio (CR 7.6), 4.274 N.m (CR 8.3), 3.598 N.m (CR 9.0), and 4.074 N.m (CR 10.0). The results of lowest value of specific fuel consumption were 4.29 m3/kWh at compression ratio (CR 7.6), 2:13 m3/kWh (CR 8.3), 1.84 m3/kWh (CR 9.0), and 2.92 m3/kWh (CR 10.0). The optimal of compression ratio was 8.3.
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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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