In order to overcome the depletion of energy resources, the production of fuel from a renewable source (green fuel) has aroused attention. The present work serves as a comparative study for green fuel production by utilizing monometallic Ni and bimetallic NiMo loaded on amine-functionalized mesoporous silica (MS). Two types of catalysts, denoted as Ni/NH2-MS and NiMo/NH2-MS, were prepared and evaluated for its catalytic activity in the hydrotreatment of waste coconut oil (WCO) at 450 ℃ under the flow of H2 gas (20 mL.min-1). Each catalysts were characterized by using X-ray Diffraction (XRD), Atomic Absorption Spectrometer (AAS), Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), and Fourier Transform Infra Red (FTIR). Study of selectivity by GC-MS showed that gasoline-range hydrocarbon, especially n-undecane, was the major compound in the liquid products generated by the two amine-functionalized catalysts prepared in this study. The result showed that monometallic Ni/NH2-MS with surface area, total pore volume, nickel loading and average pore diameter 328.68 m2.g-1, 0.25 cm3.g-1, 1.90 wt%, 3.10 nm, respectively, exhibited the best performance in producing liquid hydrocarbon and generated higher level of liquid product (77.9 wt%) than bimetallic NiMo/NH2-MS (76.3 wt%). However, it is highlighted that adding 1.08 wt% of Mo in bimetallic NiMo/NH2-MS comprising 0.83 wt% of Ni improved the catalyst selectivity towards producing higher level of gasoline-range hydrocarbon (43 wt%). The bimetallic NiMo/NH2-MS prepared was found to have surface area, total pore volume, and average pore diameter of 325.13 m2.g-1, 0.14 cm3.g-1, 3.22 nm, respectively. Copyright © 2020 BCREC Group. All rights reserved

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Bimetallic is a type of metal composite that combines two metals that form a metallurgical bond. The manufacture of bimetallic bushings by centrifugal casting has not been developed much. Recently, there is no recommendation yet for optimum temperature and speed of rotation to produce bimetallic bushings. The research was conducted to determine the rotation of the mold in centrifugal casting so as to produce a well-integrated interface. The materials used are aluminum and copper. Aluminum was melted at 750 °C, while copper was melted at 1200 °C. Molten metal was pouring alternately. First, aluminum was poured into the mold, and then after the aluminum temperature reached 400º C, copper was poured into the mold to form a bushing aluminum-copper bimetallic. The molten metal was poured into a rotating sand mold with a constant filling speed of about 0.15 kg s-1. The variations of the rotational speed of the mold were 250, 300, and 350 rpm. The result shows that the interface’s width increases as the mold rotation increases during the pouring process. Interface hardness and wear are increased compared to the base metal. Hence, centrifugal casting with 350 rpm is recommended for aluminum-copper bimetal bushing applications.

Aphasia is a language disorder caused by brain injury. This study aimed at describing how the pragmatic process and forms on words and language phonemes of those suffering from global aphasia. The study is qualitative research using case study approach. The primary data on this study were collected by purposive sampling whose subject was a global aphasia sufferer who had obtained language rehabilitation during one-year period. The secondary data were taken by using in-depth interview with the family, therapist, and subject's neighborhood. The data were analyzed by comparing the in-depth interview result and the field notes of research. The result showed that the individual with global aphasia still had pragmatic abilities, although s/he could produce meaningless words and sounds. In addition, the individual with global aphasia used gesture and intonation to help convey the idea of her/his utterence. The gestures and intonations performed by the individual with global aphasia were nodding and shaking head, and moving hands; while the forms of intonation changes were sudden change in intonation, imitating sounds, and whisper.

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