Cylinder : Jurnal Ilmiah Teknik Mesin

Friction Stir Welding pada Paduan Aluminium 6061 dan HDPE menggunakan Mesin Frais

Widodo Widjaja Basuki — 2024-04-30

Friction stir welding (FSW) is a solid-state welding method that is very simple, cheap, and in principle only requires equipment to rotate the tool and move the workpiece translationally. In this research, it was demonstrated that the FSW process of aluminum alloy 6061 and high-density polyethylene (HDPE) polymer is possible using a vertical milling machine, however, modifications need to be made to make it possible to regulate the pressure applied by the milling machine through the tool shoulder to the surface of the workpiece. Apart from that, it was also known that for each material undergoing the FSW process, it is necessary to determine the right parameter set which is a combination of rotational speed and tool feed speed to obtain optimal welding results. Too high a tool rotation speed can cause high lifting forces which can produce large porosity in the workpiece. For the HDPE FSW process, too high a tool rotation speed, which is not balanced with the increase in feed speed will provide excessive heat, causing depressions on the surface of the nugget zone.

Rancang Bangun Alat Kompres Demam Digital Suhu Hangat

Karel Octavianus Bachri — 2024-04-30

In this research, a digital fever compress device based on Arduino Uno was designed, utilizing warm temperature as a method for fever management. The device is equipped with a temperature sensor DHT, liquid crystal display (LCD), relay, and cartridge heater to create precise and controlled warm temperatures. The objective of this research is to design a digital fever compress device capable of generating warm temperatures ranging from 37.5°C to 42°C using Arduino Uno as the main microcontroller. The design process involved creating a model of temperature and tension equations, where the influential variables include ambient temperature, upper limit, and lower limit. Result shows the difference of the temperature values over time with the overall standard deviation of 1.4894, 1.6480, and 1.6217 and the overall standard deviation of the maxima and minima of 0.8085. The test results also indicated outcomes beyond the limits due to the large sampling time.

Pengembangan Lapisan Komposit 3YSZ - AL2O3 Pada Substrat Inconel Dengan Metode Electrophoretic Deposition

Jason Jeremy — 2024-04-30

Nickel-based alloys, known as superalloys, exhibit high resistance to oxidation and slow deformation at elevated temperatures, making them suitable for aircraft and gas turbine applications. However, corrosion remains a challenge at temperatures exceeding 800◦C. One solution is to coat the metal with heat-resistant layers such as YSZ and Al2O3 ceramics. Previous research indicates that adding Al2O3 above 30% has a negative impact. Therefore, a study was conducted to explore coatings with 10% and 20% Al2O3 compositions using electrophoretic deposition method at voltages of 20V, 40V, and 60V on
an Inconel substrate. The study found that the 20% Al2O3 coating had a porosity of 26% and a maximum hardness of 105.64 HV at 20V voltage.

Peluang Penerapan Desain Thinking di Industri Maritim Studi Kasus : Pencarian Jasa Docking

Marsellinus Bachtiar W — 2024-04-30

The ship maintenance industry is one of the maritime sectors that supports the economy, where ships are required by regulations to dry dock periodically for repairs and maintenance to ensure their seaworthiness. From the shipowner's perspective, the need is to find a dry dock that meets both technical and economic requirements. Innovations in business processes and drydocking business models have seen various improvements, particularly in the use of technology, automation, and operational efficiency. The implementation of Design Thinking in the maritime industry is widely open, although there are challenges in its adoption, especially due to entrenched business practices and the complexity of meeting dry dock requirements. The results obtained from the observation of the implementation efforts indicate that there are opportunities for the application of new innovations in the maritime industry. This is attributed to the openness towards new technologies and business processes, especially among the next-generation leaders of companies, who belong to the millennial or Gen Z cohorts.

Analisis Pengaruh Modifikasi Pressure Reducing Valve Terhadap Range Pressure Drop Aliran Uap

Kelly Anwar — 2024-04-30

Pressure Reducing Valve (PRV) is a control valve designed to reduce upstream pressure to downstream pressure on fluid flow. When operating, a PRV is in an equilibrium condition because of the forces acting on it, such as fluid resultant force, membrane force, and spring force. On some working conditions, a PRV cannot operate because the equilibrium is unattainable by the spring that deflects further than the maximum allowable limit and unable to produce force balancing out other forces. Therefore, a modification on the spring wire diameter from 17 mm to 20 mm is conducted without altering other PRV parts dimension and geometry. The modified spring will be analysed through analytical analysis and simulation analysis with Ansys software. On the same working conditions with the enlargement of the spring wire diameter, the deflection that once was 99,28 mm decreases to 42,64 mm and does not exceed the maximum limit at 74,375 mm so the PRV can operate on said condition and the pressure drop range increases from 7 bar to 9 bar.

Production and Performance Test of Biodiesel Produced from Waste Cooking Oil

Yosua Setiawan — 2024-04-30

Biodiesel has become an important source as a subtitution fuel for diesel engines. As an alternative fuel for diesel engines, it is becoming increasingly important due to diminishing fossil fuel reserves and the environment consequeness of exhaust gases from petroleum fuelled engines therefore, it needs to be further investigated how biodiesel blend percentage could affect the performance and emission of diesel engine. Waste cooking oil (WCO) is one of the raw material for Biodiesel. WCO that has been converted into biodiesel is made using esterification and transesterification methods. Then, biodiesel is mixed until it has the composition of B20, B30 and B50. The mixture is then tested for performance and emissions. In testing, B30 did not have a significant decrease in performance but the emission test results (opacity) were higher than B20. B50 has a significant decrease in performance when compared to B20, but has the lowest opacity test results.

Analytical Simulation of Linear Comparison of Temperature Changes Versus Time in the Heat Equilibrium Process of Mixing Two Liquids

Stephanus Ivan Goenawan — 2024-04-30

The explanation of the concept of entropy which explains that the increase in disorder in a closed system that works in advancing time comes from the second Law of Thermodynamics. In its development, Law of Thermodynamics 2 was enriched by the presence of Law of Thermodynamics 2.1 which states that the average entropy process in the forward direction will be the same or smaller than in the backward direction. The meaning of the entropy averaging process in the backward direction is that the entropy averaging process is in the forward direction but works on a heat function that mirrors the previous one, namely the heat function over time in the forward direction. Furthermore, by utilizing the Law of Thermodynamics 2.1, the results of analytical simulations can be seen comparing the level of linearity of changes in temperature over time in the process of heat flow towards thermal equilibrium in the mixing of two liquids. The results of this analytical comparison show one of the benefits of developing the second Law of Thermodynamics, namely Law of Thermodynamics 2.1.