Judul: Liquefied Petroleum Gas Performance on 6,5 HP Engine as an Alternative Fuel in Small Motorized Fishing Boat.
Abstrak: Fuel is the main commodity for fisherman who owns a motor boat to run the fishing venture. Fuel expenditure at this time became traditional fishermen problem that burden the operational cost of catching fish for the most part of the total cost to be spent and high operational cost for fishing activity, is the reason why fishermen are reluctant to sail. Therefore, reducing the fuel consumption by using Liquefied Petroleum Gas (LPG) as an alternative fuel on small motor boat can reduce daily operational cost. Converting the fishing boat from using sail and paddle to engine as the powertrain has benefited fishermen in time, effort and fishing ground scope. On the other hand dependency on subsidized fuel is very fundamental for them. Therefore, on the year 2006 the Indonesian government issued the President Decree no. 5 as a policy to develop alternative fuel so that the fishermen can reduce the subsidized fuel expenditure cost by switching to LPG which as a cheaper price on their engine boat. LPG is an unrenewable energy resource which derived from liquefied earth oil and one of the fuel that has the potential to replace or reduce the use of susidized fuel as it has been stated by some studies on LPG which can be used on land vehicles such as motorcycles, cars and watercraft such as traditional fishing boats that is using fuel and diesel motor. This can be done because the octane number of LPG is 120, this octane number is equivalent to fuel. The scope of this research was to analyze the technical and cost aspects. In terms of technical aspect was comparing the performance of LPG and fuel in the engine which was used as experiment object. The comparison was to found out how the fuel consumption and the engine and exhaust temperature difference when the engine run on LPG and fuel. Further analysis was about the cost of covering the operational costs in order to be considered for fishermen to use LPG as an alternative fuel. The objectives of this work were to analyze the technical effect of LPG compared to the fuel on 6,5 HP engine by measuring the engine and exhaust temperature and to calculate the fuel saving for a single trip by measuring measuring the specific fuel consumption, and to explicate the cost benefit from the use of LPG compared to the gasoline for fishing activity. During the experimental test, the engine speed was maintained at idling conditions of 1600, 2000, and 2500 rotation/minute throughout the experiment. In each rotation, time required by the engine to consume 50 cc of fuel and 200 gr of LPG was noted in three repetition. Similiarly for recording the engine and exhaust temperature. All collected data were collected in two phases. The engine and exhaust temperature were collected in the laboratory of Fishing Technology Development Center (BBPPI) Semarang. Fuel consumption test were performed in laboratory iv and experimental fishing trip from Tambaklorok fishing port to the fishing ground where the fisherman usually catch fish. Result showed the engine and exhaust temperature decrease when
Keyword: Bogor Agricultural University (IPB)

Judul: CNG (Compressed Natural Gas) potention as an alternative fuel for fishing ship with 11 m length.
Abstrak: Fishermen get challenge from both internal and external when doing fishes catching process, especially at fulfill his economic needs. The external factors are import fishes who lead the markets, bad weather, and high sea waves. The internal factor is high operational cost, especially from fuel costs. Majority of indonesia’s fishermen use small ship for catch fishes. Small ship is ship that use outboard engine or non GT ship. According to 2011 fisheries statistics (statistik.kkp.go.id), fishing ship that use outboard engine have amounts of 225 786. these amounts shows that outboard engine fishing ship are dominant. Statistics data also shown that non GT fishing ship are dominant. Fuel cost problem are latent problem for fishermen because it became biggest component from operational cost. Based on description above, it needs effort to reduce dependency to fuel stock, especially solar stock. One of efforts that can be done is implementation of dual fuel in fishing ship. Dual fuel is combination of solar and Compresed Natural Gas (CNG). CNG kit only suitable for ship which have breadth more than 2 m. Usage of CNG kit will added mass 80 kg on board. These added mass will affected centre gravity position and ship stability. Purpose from thi research are study about engine operation potention technically and economically when using dual fuel compare with using single fuel, analyze best location for CNG that give best stability result for the ship, study best option for potention combination from engine operational and stability. Research held at BBPPI workshop in Semarang, Central Java. This research conduct at September until December 2012 and using method experimental and numerical simulation. Data collected from BBPPI (2010) and Nugraha (2004). Data processed with microsoft excel and analyzed with multi criteria analysis. Multi criteria analysisi is analysis method that use scoring and standarization to define best potention combination. When using dual fuel, solar consumption dan total fuel costs is better than use single fuel. Superiority of single fuel locate at its horse power. Horse power from single fuel engine are 23% higher than dual fuel engine. Superiority of dual fuel are from solar consumption an total fuel costs. It superiority are 50,52 % and 17,5 % compared to single fuel. Design 3 has value 5,08 and design 1 has value 5,03. Two potension (engine operational ann ship stability) when combined shows that the best superiority occur when ship use dual fuel with CNG kit located above deck . this combination has value 8,51 from maximum value 14. Ship when using dual fuel with CNG kit located below deck is in second position with value 8,46, and the last position is ship with single fuel which have value 7,5
Keyword: CNG, stability, ship, dual fuel, multi criteria analysis

Judul: Invers dari Matriks Tridiagonal Jacobi
Abstrak: Suatu matriks berukuran n×n dinamakan matriks tridiagonal jika untuk . Karya ilmiah ini memberikan algoritma yang mudah untuk menemukan invers ( dari matriks tridiagonal Jacobi yang simetrik dan nonsimetrik. Setiap elemen pada matriks tridiagonal ini adalah bilangan real. Terdapat 3 lema dan 2 teorema untuk menentukan . Lema pertama menunjukkan persamaan utama dalam membuktikan lema-lema dan teorema-teorema selanjutnya. Invers dari matriks yang simetrik dibuktikan oleh lema kedua yang menunjukkan elemen-elemen baris ke- dari . Selanjutnya, lema kedua dilengkapi dengan teorema pertama yang menunjukkan elemen-elemen dengan . Invers dari matriks yang nonsimetrik dibuktikan oleh lema ketiga yang menunjukkan elemen-elemen dengan dan elemen-elemen dengan dibuktikankan oleh teorema kedua.
Keyword: symmetric, nonsymmetric, matrix