Judul: The Effects of Ultra Fine Bubble Addition in Diesel and Biodiesel Fuels on Carbon Emission Content and Exhaust Gas Opacity of Diesel Engines
Abstrak: Salah satu keunggulan yang dimiliki engine diesel adalah efisiensi penggunaan bahan bakar sehingga ideal untuk digunakan dalam jangka waktu yang lama serta kemampuannya untuk memproduksi jumlah torsi yang lebih tinggi dibandingkan engine bensin. Akan tetapi, salah satu kekurangan engine diesel adalah ketebalan asap pada gas buang dan kandungan emisi yang diproduksi. Salah satu cara untuk mengurangi hal tersebut yakni dengan melakukan penambahan oksigen pada bahan bakar melalui teknologi Ultra Fine Bubble. Adanya penambahan Ultra Fine Bubble atau UFB pada bahan bakar engine, dapat mengurangi kandungan emisi karbon (CO, CO2, dan HC) dan juga ketebalan gas buang. engine diesel yang menggunakan bahan bakar B100 dengan penambahan UFB juga mengalami penurunan rata-rata opasitas gas buang, kandungan CO dan HC secara berturut-turut sebesar 39,23%; 56,57%, dan 48,75% disertai kenaikan kandungan CO2 sebesar 44,73%. Disisi lain, engine diesel yang menggunakan bahan bakar Pertamina Dex dengan penambahan UFB, mengalami rata-rata penurunan opasitas gas buang, kandungan CO dan HC masing-masing sebesar 20,02%; 52,37%; dan 52,07% sementara terjadi kenaikan kandungan CO2 sebesar 10,45%., One of the advantages of diesel engines is their efficient use of fuel, making them an ideal use over long periods of time as well as their ability to produce higher amounts of torque when compared with gasoline engines. However, one of the drawbacks of diesel engines is the exhaust smoke opacity and its emission content. One way of reducing these drawbacks, is by adding Ultra Fine Bubble or UFB to the engine fuel. Diesel engines using UFB-injected Pertamina Dex, experienced an average decrease in smoke opacity, CO, and HC content by 18.17%; 52.37%; and 52.07% respectively, while simultaneously gained an increase in CO2 content by 10.45%. Similarly, engines using UFB-injected B100 also experienced a decrease in average smoke opacity, CO, and HC content by 39.23%; 56.57%, and 48.75% respectively while also gaining an increase in CO2 content by 44.73%.
Keyword: carbon emission, Diesel Engine, Ultra Fine Bubble, smoke opacity

Judul: Analysis of the Addition of Ultra Fine Bubble in Fuel Variations on Two Wheel Tractor Diesel Engine Exhaust Emission
Abstrak: Sektor pertanian merupakan salah satu sektor yang memberi dampak positif bagi pertumbuhan ekonomi. Sebagian besar alat dan mesin pertanian menggunakan enjin diesel sebagai sumber penggerak. Sementara itu gas buang yang dihasilkan oleh enjin diesel sangat berbahaya bagi kesehatan manusia. Sehingga diperlukan inovasi yang dapat menurunkan kadar emisi enjin diesel pada sektor pertanian. Teknologi ultra fine bubble (UFB) yang berkembang saat ini mampu memperkaya oksigen yang ada pada bahan bakar dan berpotensi mengurangi emisi gas buang. Penelitian ini dilakukan guna menganalisa emisi gas buang pada variasi bahan bakar normal dan ber-UFB, serta membandingkan hasil emisi dengan standar yang berlaku. Metode yang dilakukan ialah pengumpulan data hasil pengujian berbasis eksperimen. Hasil yang diperoleh ialah persentase penurunan emisi tertinggi dari bahan bakar normal ke bahan bakar ber-UFB terjadi pada bahan bakar B30. Secara keseluruhan UFB mampu menurunkan emisi terutama pada kandungan nitrogen monoksida (NO), sulfur dioksida (SO2) dan nitrogen oksida (NOx). Pada standar baku mutu emisi pembangkit listrik tenaga diesel, seluruh variasi bahan bakar sudah memenuhi standar kandungan SO2. Sementara itu B30 normal belum memenuhi standar kandungan NOx, dan Pertamina Dex normal, B30 normal, B30 ber-UFB belum memenuhi standar karbon monoksida (CO). Pada standar baku mutu Euro 2 dan Euro 4, seluruh variasi bahan bakar memenuhi standar kandungan CO dan NOx., The agricultural sector is one sector that has a positive impact on economic growth. Most of the tools and agricultural machinery use diesel engines as a source of propulsion. Meanwhile, the exhaust gas produced by diesel engines is very dangerous for human health. So innovation is needed that can reduce diesel engine emission levels in the agricultural sector. Ultra fine bubble technology which is currently developing is capable of enriching the oxygen in the fuel and potentially reducing exhaust gas emissions. This research was conducted to analyze exhaust gas emissions on normal and UFB fuel variations, as well as compare the emission results with the applicable standards. The method used is data collection based on experimental testing. The result obtained is the highest emission reduction percentage from normal fuel to fuel with UFB occurs in B30 fuel. Overall UFB is capable of reducing emissions, especially in the content of nitrogen monoxide (NO), sulfur dioxide (SO2) and nitrogen oxide (NOx). In the emission quality standards for diesel power plants, all types of fuel meet SO2 content standards. Meanwhile normal B30 does not meet NOx content standards, and normal Pertamina Dex, normal B30, UFB B30 does not meet carbon monoxide (CO) standards. In Euro 2 and Euro 4 quality standards, all fuel variations meet CO and NOx content standards.
Keyword: Bahan Bakar, Enjin Diesel, Emisi Gas Buang, Ultra Fine Bubble, Diesel Engine, Exhaust Gas Emission, Fuel, Ultra Fine Bubble

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: