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This study is focused on the utilization of the limestone from Aceh province, Indonesia, as a raw material for preparing inorganic oxide using a high thermal decomposition method. In this preliminary experiment, the limestone material was powdered, then calcined at a temperature of 900 °C for 4 hours under atmospheric pressure and modified with several concentrations of nickel element (1, 3, 5 wt%). The prepared catalyst was characterized using analytical instruments, namely X-Ray Diffraction (XRD) and Scanning Electron Microscope Energy Dispersive Spectroscopy (SEM-EDS). Based on the diffractogram of XRD, it can be known that the prepared catalyst was dominated by CaO crystals, in which Al2O3 was a minor compound. Characterization of the prepared catalyst using SEM-EDS demonstrated that the catalyst has a homogeneous morphology and uniform particle size. [ABSTRACT FROM AUTHOR]

Sound absorption characteristics of Oil Palm Empty Fruit Bunch (OPEFB) bound together by chitosan are investigated by an experimental approach. The usage of OPEFB for the sound absorber application is useful for obtaining natural fiber-based absorbers while the issue of oil palm plantation waste in Indonesia to the environment can be alleviated. Moreover, with the chitosan bio-binder, targeted porosity structures in form of kinematic and non-kinematic porosities are expected to be present to deal with the performance at low frequency. Here, we investigate the presence of both porosity types using the Scanning Electron Microscope (SEM) technique while associated sound absorption characteristics are obtained by the impedance tube measurement under normal sound incidence. The relations of the structure and resulting sound absorptions are discussed. [ABSTRACT FROM AUTHOR]

Cassava (Manihot esculenta) is an agricultural product that abundant in Indonesia and mainly used as source of carbohydrate consumption. This study aimed to utilize the waste water of cassava for producing the bacterial cellulose (BC) as a starting material to form novel composite of Ag/BC. The composite was prepared by impregnating silver solution into the BC network and followed by reduction process using NaBH4. The morphological surface of the Ag/BC composite was evaluated using scanning electron microscope (SEM) and Energy Dispersive X-ray (EDX). The results showed that the network of Ag/BC composite consist of fibril with width below 100 nm. The SEM-EDX pattern also presented that silver particles were incorporated into the BC network. Meanwhile the functional group of the Ag/BC composite was also characterized using Fourier-transform infrared spectroscopy (FTIR). The antibacterial activity of Ag/BC composite from cassava was performed against 5 bacterial pathogens, namely Staphylococcus aureus (SA), Salmonella typhi (ST), Escherichia coli (EC), Bacillus subtilis (BS), and Pseudomonas aeruginosa (PA). The result showed that Ag/BC composite could inhibit five pathogen bacteria with good result with inhibition zone in the range of 7.11±0.3 to 8.22±0.7 mm. This study showed the potential application of Ag/BC composite from cassava waste water as a natural agent for cosmetic and pharmaceutical purpose, especially as an antimicrobial agent. [ABSTRACT FROM AUTHOR]

Cellulose is one of the renewable natural resource materials that can be found in Indonesia. Cellulose can be synthesized from various parts of plants, such as pine trees. Pinewood waste is also known for its high amount of cellulose content. Thus, cellulose can be isolated from its pinewood waste. The necessary process in isolation is the removal of lignin and hemicellulose by extraction method using some solvents and heating. The bleaching method is carried out with hydrogen peroxide solution. This resulted in white bright cellulose with a yield of 58.40%. Cellulose result was obtained in the form of microcrystalline and further characterized by some instrumentation similar as x-ray diffractometer (XRD), scanning electron microscope (SEM), and Fourier-Transform infrared spectroscopy (FTIR). The crystallinity index of cellulose resulted from the isolation process is 55.20%, with morphological surface in the form of multisized agglomerated long fibers with an average particle size 125 µm. FTIR spectra showed some peaks at specific wavenumber indicating a typical function group of cellulose. Therefore, it can be concluded that pinewood waste can be used as a high-value cellulose material, with an easy and environmentally friendly method. [ABSTRACT FROM AUTHOR]

Indonesia supply accounts for 16 % of the world's lateritic nickel ore, with the estimation reaching 1.391 billion tons. The process of refining lateritic nickel ore can be considered as one of the main problems faced by the world mining industry, taking into account the economic and energy aspects. This research was carried out to investigate the effect of sulfur in reductants on the selective reduction process of saprolitic nickel ore. This research used saprolitic ore using 10 wt.% additives (sodium sulfate). Two kinds of coal reductants containing 2.68 % and 5 % of sulfur were also used. Nickel ore, additives, and reductant were mixed homogenously prior to the pelletization into a diameter of 10-15 mm. The reduction of pellets was carried out at temperature variations of 950, 1050, and 1150 °C for 60 minutes, followed by magnetic separation using 400-600 Gauss of the magnetic field to separate magnetic-concentrate, which contains ferronickel, and non-magnetic tailing, which contain impurities. The reduced ore characterization was performed by using X-ray Diffraction, Optical Microscope, X-ray Fluorescence, and Scanning Electron Microscope. This research showed that the optimum nickel grade and recovery were obtained using 2.68 % of sulfur content in coal reductant. [ABSTRACT FROM AUTHOR]

There are many cocoa pulp wastes in Indonesia; unfortunately, still a few of them has been utilized. Cocoa pulp contains high enough of cellulose and hemicellulose that able to be converted to reducing sugar with hydrolysis process. However, it also has an immense lignin content that inhibits the enzymatic hydrolysis process. How to reduce lignin contents will be studied in this research by comparing pretreatments using NaOH solution and using NaOH-H2O2 mixture solution. Lignin, hemicellulose, and pectin contents were analyzed by using UV-Vis spectrophotometer and gravimetric method was used to analyze cellulose contents. Morphology, and crystallinity index (CrI) were analyzed by using Scanning Electron Microscope (SEM), and X-ray Diffraction Pattern (XRD), respectively. The experimental results showed that pretreatment with NaOH-H2O2 was the best method with a decrease in lignin content up to 85.67%. This result is supported by SEM results showing that with the pretreatment, the previously smooth surface of cocoa pulp becomes rough surface and many void/cracks. XRD results show that the CrI of cocoa pulp waste decrease after being chemically pretreatments, especially in NaOH-H2O2 pretreatments. COD removal with NaOH-H2O2 is the highest than others. Total Solid (TS) and Volatile Solid (VS) decrease with the increasing of fermentation time. Contribution of acetic acid in Volatile Fatty Acid (VFA) total is higher than others and achieved maximum value after 15 days and decrease rapidly after 20 days and being constant after 25 days of fermentation. This result agrees with biogas production and resulting methane with concentration of 66.07% and yield of 0.734 m3 CH4/kg VS. [ABSTRACT FROM AUTHOR]

Silicon Dioxide (SiO2) compound can be obtained from the extraction of Salak Pondoh skin. The initial process is that the Salak Pondoh fruit is peeled and the skin is dried with the help of sunlight for one day. After a day has passed, dried skin of Salak Pondoh fruit will be burned to ash using an oven at 350°C for 2 hours. After it has been turned to ash, then it's roasted further with temperature variations of 550°C, 600°C, and 650°C. The ash of Salak Pondoh skin was analyzed by using SEM (Scanning Electron Microscope) which showed that the surface of the ash of Salak Pondoh Skin, an analysis of EDX (Energy Dispersive X-Ray) which showed the content of Salak Pondoh skin, and FTIR (Fourier Transform Infra-Red spectrophotometer analysis) which showed that the functional group content of SiO2 from Salak Pondoh skin was O=Si=O at wave number 1651.322 cm−1. The analysis shows that Silicon Dioxide can be obtained from Salak Pondoh's skin. Research on Silicon Dioxide from the waste of Salak Pondoh zalacca skin biomass is very important in Indonesia as a basis for electronics, computers, and natural-based Silicon implants. [ABSTRACT FROM AUTHOR]

Due to a high number of bone fracture cases in Indonesia, the development of bone scaffold is becoming a solution to improve damaged bone structure. In bone scaffold fabrication, several parameters must be met such as morphology, pore size, and antibacterial properties. One of the antibacterial agents that can be used for the bone scaffold is silver nitrate (AgNO3). In this study AgNO3 with various concentrations (0.005, 0.01, 0.02, and 0.1 M) was added in HA-chitosan bone scaffold that was synthesized via freeze drying process. The synthesis resulted in bone scaffolds in the form of an interconnected porous structure. In this study, Fourier transform infrared (FTIR), scanning electron microscope (SEM), energy dispersive x-ray (EDX), and antibacterial test were carried out. SEM-EDX results showed porous morphology with an average size of 68.32 µm in bone scaffold without AgNO3 and 16.66 µm in the bone scaffold with the addition of AgNO3. Antibacterial testing showed that the higher the concentration of silver nitrate used, the greater the diameter of the inhibitory zone produced. [ABSTRACT FROM AUTHOR]