Oil palm's empty fruit bunches (OPEFB) as the waste from oil palm industry is one of lignocellulosic biomass feedstocks for a potential second-generation bioethanol production. Pretreatment process is a key process for producing bioethanol. OPEFB treated is expected to give better properties used for bioethanol production. This research aims to study the effect of pretreatment process by combining chemical and irradiation to OPEFB's properties as raw materials in the hydrolysis reaction producing sugars which will be fermented into ethanol. The raw materials are characterized in term of crystallinity, chemical structure, chemical content, and surface morphology. Analysis results of chemical content showed that cellulose and hemicellulose content increased significantly while lignin content decreased significantly after pretreatment. The crystallinity measured by X-Ray Diffraction (XRD) showed that after pretreatment, their crystallinity index and the crystallite size increased significantly. While, the surface morphology and composition shown by Scanning Electron Microscope/Energy Dispersive X-ray spectroscopy (SEM/EDX) showed the changing in morphology surface and dominantly composed by carbon and oxygen.

Synthesis of austenite stainless steel using extracted minerals from Indonesian mines has been carried out. It is namely A2 steel. The main raw material of making non standard steel A2 is granular scrap iron, nickel, iron-chromium, iron-manganese, and iron-silicon. It is obtained from non standards. A component of A2 steel consists of 15,42%Cr, 25,01%Ni, 0,32%Mn, 0,96%Si and 0,34%C with impurities of 0,039%V and 0,051%Cu. Characterization using neutron diffraction technique shows the first four Bragg peaks of (111), (200), (220) and (311). A machining process was performed to make a plat from ingot. After the machining process, intensities and FWHM of the first two Bragg peaks of (111) and (200) are quite the same. But the intensity of the peaks (220) and (311) changes. It is calculated that for (220)peak the decreasing intensity about 51.6% and increasing FWHM about 0.14%, whereas for (311) peak the intensity increase about 40.2% and the FWHM decrease about 3%. Furthermore, the material obtained from the machining process is used as a reference to the condition of the material without rolling. After being subjected to rolling up to 70% thickness reduction, crystal orientation changes from highest intensity with a sequence of (200), (111) and (220) to (220) (111) and (200) with highest increasing intensity about 2.25 times at (220). Quantitative analysis of texture after the rolling process is shown in pole figures of (111), (200) and (220). It is characterized that crystals are oriented mainly to {110} <113>, texture index is 1.0671.

Oil palm empty fruit bunch (OPEFB) is a potential type of lignocellulosic biomass for second-generation bioethanol production. The pretreatment process is an important process in the series of processes to produce bioethanol. This research aims to study the effects of pretreatment process by using electron beam irradiation to OPEFB's characterization as raw materials for the hydrolysis reaction to produce monomer sugars which will be fermented into ethanol. The untreated and treated OPEFB are characterized in terms of their physical and chemical properties. Analysis results of the compositional analysis by using NREL/TP-510-42618 method show that after pretreatment by using electron beam irradiation, OPEFB's total lignin content is changed little while its cellulose and hemicellulose contents tend to decrease with increasing irradiation dose. X-ray diffraction (XRD) analysis shows that there is a decrease of crystallinity compared to untreated OPEFB, except for 200-kGy irradiated OPEFB. The highest decrease of crystallinity was shown by 300-kGy irradiated OPEFB. Further, crystallite sizes of treated OPEFBs are not significantly different from the untreated, except for the 200-kGy irradiated OPEFB. Irradiation pretreatment also increases specific surface area, pore volume, and pore size. The IR spectra analysis show the absorption of cellulose, hemicellulose, and lignin.

No abstract

THE INFLUENCE OF HEAT-TREATMENT TIME AND TEMPERATURE ON THE THERMO-PHYSICAL PARAMETERS OF ASSAB-CORAX STEEL.X-ray diffraction experiment was carried out on commercial Assab-Corax steel sample. The polished samples are then heated to various temperature for different holding time; 200 o C for 4 hours, 300 o C for 4 hours, 400 o C for 6-, 8-, 12-and 16 hours, 500 o C for 4 hours and 600 o C for 4 hours. The refinement of the diffraction intensity was carried out using the Im3m model, and the results show that the Carbon atoms are distributed among the base position in the body centered cubic unit cell at the eight-fold octahedral interstitial sites. Using the refined structural parameters, thermo-physical properties such as Debye temperature and coefficient of thermal expansion are calculated. From the results of the analysis it could be concluded that Debye temperature in Assab-Corrax steels tend to decrease with increasing heat-treatment time but tend to increase with heat treatment temperature. The coefficients of linear expansion also tend to decrease with increasing heat-treatment time and tend to increase with heat treatment temperature. Although the patterns are different, for example when the Debye temperature reaches its peak value for heat treatment time of 8 hours, the coefficient of linear expansion would reach its low point at this time. Therefore, the general finding is that both treatmenttemperature and -time are influential to the physical properties of Assab-Corrax steels and xray diffraction methods could be utilized in elucidating these important findings.