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: Modifikasi Konverter Biogas untuk Motor Bensin
Abstrak: Biogas contains methane at about 60-65% which is potential to be used as fuel. Biogas is also possible to replace gasoline as fuel on internal combustion engine. A new design of biogas converter is needed to optimize biogas deployment as fuel on motor gasoline fuel. . The objectives of this research are modifying and testing biogas converter. This biogas converter consists of some main components, including venturi, venturi housing, choke, throttle, chamber tube and flange. The design of biogas converter could be worked with existing governor mechanism of the engine. Design of biogas converter are the gas cylinder 1 (Ø 50 × 80 mm), gas cylinder 2 (Ø 40 × 130 mm) and without gas cylinder. The experiment has been tested by measuring engine maximum motor rotation and pump discharge water. According to the experimental result the biogas converter with first gas cylinders show better perfome than the gas cylinder 2 or without gas cylinder, so it can optimize biogas deployment as alternative energy to drive the motor gasoline fuel. The pump discharge water 6.62 litres/min at 2390 rpm and maximum motor rotation use of biogas converter is 3390 rpm.
Keyword: Biogas converter, Internal combustion engine, Alternative energy, Biogas

Judul: The Fern of West Timor  East Nusa Tenggara
Abstrak: Based on this study there are 58 species belonging to 36 genera. They are Achrosticum (1 species), Adiantum (5 species), Amphineuron (3 species), Asplenium (4 species), Athyrium (1 species), Belvisia (1 species), Botrycium (1 species), Ceratopteris (1 species), Christella (4 species), Ctenitis (1 species), Ctenopteris (1 species), Cyathea (1 species), Davallia (2 species), Dennstaedtia (1 species), Diplazium (2 species), Doryopteris (1 species), Drynaria (2 species), Dryopteris (1 species), Gleichenia (1 species), Heterogoniurn (1 species), Humata (1 species), Lycopodium (1 species), Microlepia (1 species), Microsorium (1 species), Nehprolepis (2 species), Oleandra (1 species), Platycerium (1 species), Pleocnemia (1 species), Pteris (5 species), Pyrrosia (1 species), Sellaginela (1 species), Selliguea (1 species), Sphaerostephanos (2 species), Tectaria (1 species), Trichomanes (1 species), and Vittaria (1 species).
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