Judul: Analisis Penambahan Oksigen pada Bahan Bakar dan Intake Mesin terhadap Performa dan Emisi Gas Buang Mesin Diesel
Abstrak: Mesin diesel masih banyak digunakan pada berbagai sektor seperti transportasi, industri, dan pertanian dikarenakan berbagai keunggulannya. Perkembangan jumlah penduduk hingga kebutuhan manusia pun berbanding lurus dengan penggunaan mesin diesel dimana hal tersebut menjadi penyebab masalah pencemaran udara yang semakin meningkat. Penambahan oksigen pada bahan bakar dengan menggunakan Ultra Fine Bubble serta penambahan oksigen ke katup intake berpotensi meningkatkan efektivitas pembakaran pada mesin diesel karena kandungan oksigen yang menjadikan reaksi pembakaran menjadi sempurna. Penelitian ini bertujuan untuk mengetahui dan membandingkan hasil performa serta emisi pada bahan bakar B0 dan B35 setelah dilakukan dua perlakuan tersebut. Penelitian dilakukan dengan metode eksperimen dan dilakukan dua pengujian, yaitu uji karakteristik bahan bakar dan uji kinerja. Kedua perlakuan menghasilkan performa yang meningkat dan kandungan emisi CO, SO2, NOx, dan HC yang menurun. Perlakuan penambahan oksigen ke katup intake lebih efektif daripada penambahan oksigen ke bahan bakar., Diesel engines are still widely used in various sectors such as transportation, industry, and agriculture due to their various advantages. The development of the population to human needs is directly proportional to the use of diesel engines which is the cause of the increasing air pollution problem. The addition of oxygen to the fuel using Ultra Fine Bubble and the addition of oxygen to the intake valve has the potential to increase the effectiveness of combustion in diesel engines due to the oxygen content which makes the combustion reaction perfect. This study aims to determine and compare the results of performance and emissions on B0 and B35 fuels after the two treatments. The research was conducted using the experimental method and two tests were carried out, namely the fuel characteristics test and the performance test. Both treatments resulted in increased performance and decreased CO, SO2, NOx, and HC emission content. The treatment of adding oxygen to the intake valve is more effective than adding oxygen to the fuel.
Keyword: Performance, Exhaust Gas Emissions, Diesel Engine, Oxygen Addition, Ultra Fine Bubble

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.
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