The propeller shaft is part of the ship which transmitting rotation from engine to propeller. The shaft is also used in small-medium size of fisherman boat. In order to reduce the cost of production, dissimilar metal bases are used by joining Steel ST41 and 316L Stainless Steel in process. This research was conducted to analyze effect of welding electrode towards tensile strength, macrostructure, and microstructure of Steel ST41 and 316L Stainless Steel welded metal. Two variations of electrode that used in this paper were E309-L and E6013 with Shielded Metal Arc Welding process (SMAW). The other parameter such as current was set at 80 A and voltage was set at 20 V with 20 mm/min welding travel speed. The results of tensile test show average tensile strength max (σmax) of E309-L and E6013 electrode were 581,42 MPa and 599,24 MPa respectively. These results show that welding process is increasing the maximum tensile strength from base material strength level. The microstructure test interpretation shows E309-L electrode has lower possibility to create delta ferrite in HAZ (Heat Affected Zone) rather than E6013 electrode. This means welding process with E6013 tends to have lower corrosion resistance.

Shape Memory Alloy (SMA) have a unique phase transformation behaviour from Martensite to Austenite, it can be change only with small increasing of temperature.  The phase transformation in SMA occur in hysteretic manner. So that, it is important to understand how phase transformation affect the coil spring stiffness constant in the SMA. The NiTi SMA are used to construct an experiment. This experiment conduct using a test bench that developed by the author. The specimen will be heated using variety of temperature with a static load, so that the Δ can be measured and used to compute the stiffness constant for every different temperature. The SMA coil spring is modelled as spring- mass- damper system with 1DOF. From this paper concluded that the heating phase transformation of NiTi start at 45 ֯C till 62 ֯ C. The value of spring constant vary based on the Δ of NiTi and its phase transformation during heating. At some point, there is no more phase transformation, so that the value of spring constant will not change. The result of this paper can be used for further improvement in the vibration control of Shape Memory Alloy. Keywords : Spring, Actuator, Control, Vibration, Material

Sirih merah merupakan tanaman obat di Indonesia yang dibudidayakan secara stek. Untuk mengurangi tingkat kematian stek, dapat menambahkan zat pengatur tumbuh eksogen dengan metode perendaman dan penggunaan komposisi media tanam yang sesuai. Tujuan penelitian untuk mengetahui pengaruh lama perendaman ekstrak bawang merah terhadap pertumbuhan stek sirih merah dan komposisi media tanam yang paling baik. Penelitian menggunakan Rancangan Acak Kelompok Lengkap dua factor, yaitu lama perendaman ekstrak bawang merah (30 menit, 60 menit, 90 menit) dan komposisi media tanam ( tanah, tanah + arang sekam + pupuk kandang sapi  (1:1:1), tanah + arang sekam + kompos daun bambu (1:1:1), tanah + arang sekam + vermikompos (1:1:1)). Hasil penelitian menunjukkan bahwa Interaksi antara perlakuan media tanah + arang sekam + pupuk kandang sapi dengan lama perendaman 30 menit dan 60 menit, media tanah + arang sekam + kompos daun bambu dengan lama perendaman 30, 60, dan 90 menit serta media tanah + arang sekam + vermikompos dengan lama perendaman 60 dan 90 menit menghasilkan persentase hidup stek yang tinggi dan tidak berbeda nyata. Lama perendaman ekstrak bawang merah 90 menit lebih baik dari perendaman 30 menit dalam mempengaruhi bobot kering akar. Komposisi media tanam tanah + arang sekam + kompos daun bambu merupakan komposisi media paling baik pada pertumbuhan stek batang sirih merah, yaitu pada parameter tinggi tunas 28 HST, tinggi tunas 56 HST, tinggi tunas 70 HST, bobot segar akar, dan bobot segar tunas.   Kata kunci : Sirih Merah, Stek Batang, Lama Perendaman, Media Tanam

Abstract. In the Ngadirejo sugar plant, sprocket shaft on the east C2 rake conveyor at the boiler station always failure every year. This conveyor is used for the process of fuel dregs supply at the boiler station. In this research, the analysis of failure and fatigue with the finite element method in Ansys will be carried out. The material analyzed is HQ705 with static loading. The analysis carried out includes static structural analysis and fatigue analysis on the sprocket shaft. Based on this analysis, found that the maximum displacement is 0.001163 m, the maximum equivalent stress is 71.8 MPa, the minimum life is 17.237 cycles, the maximum shear stress is 38.44 MPa, the minimum safety factor is 0.557744. The failure in the FEM analysis results in accordance with the actual failure location. The redesign process was carried out with HQ709 material, with this material the minimum life value is 50539 cycles.

The static analysis of a copper roller shaft is performed. The copper roller shaft consists of bushing, pen roll and roller. All of those components g4bconsist of different materials. Thermal steady state and statical analysis is performed in order to investigate the thermal effect of high temperature copper slab on the roller shaft. The copper slab temperature is 1200 OC. Based on this work obtained that the maximum total deformation is 0.0050523 m, maximum equivalent stress is 41600 MPa, maximum life cycle is 1011, total heat flux maximum is 879910 W/m2 and the maximum damage occur in the pen roll component.