No abstract

In this study, an environmentally friendly composite was prepared from cantala fiber and recycled high-density polyethylene. Alkali treatment was utilized to improve the fiber–matrix interface of cantala fiber. The alkali treatment was carried out with a 2% NaOH solution for periods of 0, 4, 8, 12, 16, 20, and 24 hours. Various recycled high-density polyethylene composites reinforced with treated and untreated short cantala fiber were produced by hot press. The tensile and impact properties of the composites were examined to reveal the effect of alkali treatment. Changes in fiber–matrix bonding were investigated via composite fractography using scanning electron microscopy. A study of fiber morphology and other supporting tests, such as the fiber tensile test, X-ray diffraction, and Fourier transform infrared microscopy were also carried out. The results show that the addition of alkali-treated fiber to recycled high-density polyethylene composites enhanced the composites’ tensile and impact performance: Tensile strength improved by 15.5% and impact strength by 24.8%.

The gas porosity is one of the most serious problems in the casting of aluminum. There are several degassing methods that have been studied. During smelting of aluminum, the intermetallic compound (IMC) may be formed at the interface between molten aluminum and solid steel of crucible furnace lining. In this study, the effect of degassing treatment on the formations of IMC has been investigated. The rectangular substrate specimens were immersed in a molten aluminum bath. The holding times of the substrate immersions were in the range from 300 s to 1500 s. Two degassing treatments, argon degassing and hexachloroethane tablet degassing, were conducted to investigate their effect on the IMC formation. The IMC was examined under scanning electron microscope with EDX attachment. The thickness of the IMC layer increased with increasing immersion time for all treatments. Due to the high content of hydrogen, substrate specimens immersed in molten aluminum without degasser had IMC layer which was thicker than others. Argon degassing treatment was more effective than tablet degassing to reduce the IMC growth. Furthermore, the hard and brittle phase of IMC, FeAl3, was formed dominantly in specimens immersed for 900 s without degasser while in argon and tablet degasser specimens, it was formed partially.

Cattle farms produce waste which consisted of cow excrement in the form of solid, liquid, gas or cattle feed residual. Utilization of cow manure waste into organic compost requires proper processing technology which includes the technology of solid manure pulverizing and the technology of mixing raw materials. This research focuses on designing a cattle dung waste pulverizer. The methods used are numerical calculations, simulations using the Fusion 360 software, and fabrication based on Design for Manufacture and Assembly (DFMA). The main parts of the design include pulverizer, engine frame, cover (input and output hoppers), diesel motor, transmission belt and pulley. The safety factor obtained for the frame section was 4,645, for the cover section was 11.3, and for the counter section was 2,009 with assumptions of uniform load distribution of 20000 N. The power required for the design was 6.6 HP. The cattle dung waste pulverizer was built and tested using a diesel motor with a maximum power of 13 HP. The cattle dung waste pulverizer's capacity was 1500 kg/hour.

The effect of load and thickness variation on stress analysis of monocoque frame of electric city car using FEM AIP Conference Proceedings 1788, 030077 (2017) Abstract. This paper presents a simulation Finite Element Analysis (FEA) model of electric trike frames. The model of electric trike frame is a standard bicycle frame with addition modification on the back side for battery pack component and passenger loads. The electric motor is driven to put in front wheel for easy maintenance. Due to gain maximum safety in the passenger area and easy assembling, the frame is manufactured by circular steel tube in the front side and square steel tube in the back side. FEA simulation has been investigating proper model based on steel tube profile. The profiles is circular and oval steel tube 1.65mm thickness, (1, 1 ½, and 1 ½) inch diameter in front and square steel tube 2 mm thickness, (30x30, 40x40 and 50x50) mm size in the back. The support tube of the electric bicycle frame is similar to the National Standard road bicycle (SNI).The validation of this simulation is using experiment method and adaption method for optimizing iteration time and accuracy. The result of the simulation is a factor of safety. Von misses stress distribution from simulation result is showed the critical are in joining tube under driver of the frame structure. The oval tube is reached safety factor better than the circular tube, and it's had a better performance against the vertical load. The best variable is variable 3 oval tube 56.6x40 mm diagonal size with 1.65 thickness. It maximum passenger load is 700Kg. It can be a recommendation to redesign future frame of the electric bicycle.