Search

In this study, Magnesium metal matrix was reinforced by multi-walled carbon nanotubes (MWCNTs) in order to observe the microstructure and the mechanical properties of the composites. The MWCNTs-Reinforced based magnesium MMC was performed using powder metallurgy process with MWCNTs loading are: 0, 0.1, 0.3 and 0.5 %. The sintering process was conducted at two different temperatures at 600oC and 650oC by flowing argon gas during the process with the same holding time of 2 hours. The effect of temperature sintering on the microstructure and microhardness was observed. The experiment result exhibited that the porosity of composites was increased by increasing the content of MWCNTs observed by metallography. The mechanical properties were investigated by hardness Vickers showed that the content of 0.3 % MWCNTs gave the highest value of 46.5 HV at T 600oC, whereas the content of 0.5 % MWCNTs showed the highest microhardness with the value of 64.6 HV. The microhardness of MMC in the same amount of MWCNTs at T 650oC is higher than microhardness value of T 600oC due to the effective load sharing between reinforcement of MWCNTs and magnesium matrix. [ABSTRACT FROM AUTHOR]

Motorcycle maintenance is one of the key factors to obtain good motorcycle performance and to avoid engine damage. One of the maintain that must be done is cleaning and adjusting the carburetor. On a conventional type motorcycle the number carburetor is equal to the number of engine cylinders. Setting the supply of air and fuel in the two-cylinder engine motorcycle, which have two carburetors is more difficult than setting the carburetor on a single cylinder engine. Because the arrangement of the supply of air and fuel between the carburetor with one another must be the same (synchronous). Therefore, a two-cylinder motorcycle carburetor synchronous detection device was made. The purpose of this research is to create a device that can help motorcycle technician to determine the synchronous state when adjusting the air and fuel supply on a two-cylinder motorcycle carburetor and can help rider to know synchronous condition of the carburetor via smartphone. This research uses arduino mega microcontroller, nodeMCU ESP8266, MPX5700 sensors, TFT LCD display and smartphone. The method used in this research is by compare pressure measurements carburetor synchronous device with a vacuum tester owned by an authorized dealer. From the results of the research, it is known that the carburetor synchronous detection device has the largest error percentage is 17% with the smallest percentage of accuracy is 83%. IoT systems on smartphones can display negative pressure measurement graphs with an interval 1 second from the LCD display. [ABSTRACT FROM AUTHOR]

Strain gage is a very important part of a load cell, with a function to detect the magnitude of the change in distance dimensions caused by a force element, aircraft configuration, wings are important components because almostall of the existing load is supported on them so that the wings are the main determinant of performance. In aircraft, theStrain gauge sensor which is needed in this study, using a Type Sensor 10/120 LY 11 sensor, the test must enter the 63KN resonance machine alignment test using the strain gauge method, in the form of stress (tension) and strain (strain).given to the load cell, after that the strain gauge which is a force sensor will translate this input in the form of resistance,strain and stress on the specimen showing numbers below -100 to 100, but this number is considered good because it does not exceed the number specified in the tolerance category. The allowable deviation of the flashlight point is : 5%, Calculated from (Final designation value- transducer flashlight point value) / transducer flashlight point value x 100%. The above allowable flashlight deviations apply to both bending and torsion. [ABSTRACT FROM AUTHOR]

Common problems with slaughtering knives that are often encountered are poor quality sharpness and relatively fast dulling of the blade. Traditionally manufactured slaughter knives are more commonly used than factory production knives. Through this research, it will be tried to compare the mechanical properties and microstructure of one of the factory-produced knives with the brand X and two experimental knives made traditionally. Brand X knives have an average hardness of 57.7 HRC on the outside and 614 HRC on the inside. The experimental knife material is leaf spring for off-road car brand W with a hardness value of 42.8 HRC, carbon content of 0.67%, and leaf spring for off-road car brand H with a hardness of 43.6 HRC, carbon content of 0.58%. The study was initiated by hardening the samples of the two types of leaf springs. The austenizing temperature is 850°C using wood charcoal, water cooling media and used car engine oil, the temperature is 29°C then tempered at a temperature of 250°C. Furthermore, the experimental knife is made by forging a hand hammer. The plating variable is made the same, it's just that the selected cooling medium is oil. From the photo of the microstructure of the two experimental blades, the structure is similar to the X blade, namely martensite and the appearance of chromium carbide. The results of the hardness test showed that the average hardness value on the outside of the X knife was 57.6 HRC, and 615 HV on the inside of the knife. The average hardness of the outside of the experimental knife reached 56-57.5 HRC, and 620-627 HV on the inside of the knife. Thus, it is concluded that although the factory and experimental knives differ in chemical composition and production process, the optimum hand forging and heat treatment makes the hardness and microstructure of the experimental knife close to the factory-produced X knife. [ABSTRACT FROM AUTHOR]

High-Temperature Gas-Cooled Reactor is one of the Generation IV reactors, which is currently one of the most advanced small modular reactors and ready for commercialization, such as indicated by the criticality of HTR-PM 210 Mwe in September 2021. The safety of reactors relies on the Triso fuels, which creates low power density in the core. The surrounding reflector graphite of the core maintains the inertial behavior during the accident, avoiding any core melt and minimizing any primary circuit structural failure damage. These fuels and graphite reflectors are inside the reactor pressure vessel, including the required instrumentation and shutdown system. This means that the pressure vessel design and characteristics are essential to maintain the overall safety of the HTGR operation during normal and accident conditions. Therefore, this research aims to demonstrate the design of the HTGR RPV using appropriate software modeling. The research is carried out to model the reactor pressure vessel of the HTGR using Solidwork software based on the conceptual design of the experimental power reactor in Indonesia. Before the model was developed, the literature review and preliminary investigation were also conducted to understand the latest trend technology. The model is later characterized by providing static mechanical loads under normal operating conditions. The results show that the design conceptual which is implemented in the 3D model can satisfy the safety and provide additional confirmation parameters for further investigation and detailed design. [ABSTRACT FROM AUTHOR]

Analysis of manufacturing rectangular holes in SS 304 material by electrochemical machining method (ECM) was carried out to determine the most optimal parameters for the outcome of surface roughness and Material Removal Rate (MRR) in a period of time. In this study. the machining process was carried out in a static state. where there was no flow of NaCl solution or movement of the anode. Variations gape within anode and cathode (workpiece), voltage, and type of NaCl are applied in this study. The voltages used are 10, 20, and 30V at temperatures of 30 °C. The types of solutions used were NaCl (90 wt% and 70 wt% water). The machining process is carried out in cells made of acrylic with a solution volume capacity of 140 ml. In this study SS 304 is used as anode and cathode which is connected by a connecting cable to a DC power supply. The result was ECM with NaCl (90% water) solution at 10 V, which is the optimal parameter. Then. the specimen will be observed using an optical microscope to determine the surface topography. The results of MMR for NaCl (70% water) solution at 30 V shows good condition. However, the parameter of surface roughness was not expected. [ABSTRACT FROM AUTHOR]