Advanced Materials Research Vol. 1113

Abstract: Selection of suitable activation agent is important in order to produce high surface area of activated carbon. The present study was undertaken to develop high surface area of durian shell activated carbon (DSAC) using different chemical activation agents which were potassium hydroxide (KOH) and phosphoric acid (H₃PO₄). Surface porosity and surface area were directly measured from scanning electron microscopy (SEM) and surface area analyzer, respectively. For the optimum condition, it showed that H₃PO₄ treated DSAC had the highest surface area which was 257.50 m²/g compared to KOH treated DSAC which was 13.10 m²/g. H₃PO₄ treated DSAC also showed the highest micropore surface area, external surface area and total pore volume with 191.22 m²/g, 66.28 m²/g and 0.149 cm³/g, respectively. SEM result showed that H₃PO₄ treated DSAC had a well pronounce porosity than durian shell char. Surface area and surface porosity were important in an adsorption process.

Abstract: The aim of the present study report on the adsorption performance of alginate bead (AB) and mangrove-alginate composite bead (MACB) bead adsorbents for the removal of Pb(II) ions from aqueous solution. The effects of pH and initial concentration with contact time on the adsorption properties of Pb(II) onto both adsorbent were investigated and were described by isotherm and kinetic studies. The isotherm adsorption data were fitted well to Freundlich isotherms for both beads and the maximum adsorption capacities of the AB and MACB beads were 29.02 mg g-1 and 10.84 mg g-1, respectively. The kinetics adsorption data were best described to a pseudo-second-order kinetic models showing that the MACB beads had a higher kinetic adsorption rate at 2.6084 g mg-1 min-1 compared to AB at 0.7043 g mg-1 min-1.

Abstract: Oil yield extraction from Phoenix dactylifera seed was compared at 50°C based on highest oil yield results using supercritical carbon dioxide extraction method. The comparison was based on the efficiency of the method to extract high quality pure oil without addition of organic solvent. Time taken to extract the oil was also evaluated as part of the method’s performance. Analysis of component in the oil was done using gas chromatography equipped with mass spectrometry (GC-MS). Oleic acid revealed to be the main fatty acid in Phoenix dactylifera seed oil, followed by palmitic acid, lauric acid, ascorbyl palmitate and others.

Abstract: Alkanolamines based carbon dioxide absorption from flue gases remains the most industrially implemented technique. The effective design of absorbers and associated equipment requires robust thermodynamic and kinetic models thus, instigating research efforts in chemical speciation and characterization of CO₂ loaded alkanolamine solutions. In this study, the potential of Raman spectroscopy has been investigated to determine the in situ chemical speciation in MDEA – CO₂ – Water system. The Raman spectra have been fitted to thermodynamic values using principal component regression. Results are in good agreement for carbonate, bicarbonate, MDEA and protonated MDEA chemical species.

Abstract: Aquilaria is a special tree that has been awarded to the earth. Aquilaria spp. which belongs to the family Thymelaeceae is one of the most precious trees is the world. Agarwood or gaharu is the name of the resin produced by Aquilaria spp. Historically, agarwood has widely been used as medicine. It was also being used for perfumes, incense and religious purposes in Muslim, Buddhist, Hindu, Christian, and Jewish societies. In order to discover the new uses of the agarwood, knowledge of the chemical constituents inside the plant need to be known. Aquilaria spp tree can be divided into two parts which is bark and leaves. Recently, several studies have been conducted to examine the chemical composition found in Aquilaria spp tree. However, there is still no specific detail documentation on the chemical compounds present in Aquilaria leaves. In this study, Soxhlet extraction method has been used to withdraw the compounds from the leaves. From the results obtained, it shows that extraction of compounds by using methanol was more effective. This was due to the higher polarity inside the methanol. Other than solvents, the samples preparation also gave an effect towards the final results. There were two different types of samples that have been used for this study which are fresh and dried A. malaccensis leaves. The obtaining results showed that more compounds have been extracted from the dried sample. It can be conclude that moisture content in the sample also plays a role in identification of compounds inside the A. malccensis leaves

Abstract: The production of xylanase by Aspergillus niger ATCC 16404 via solid state fermentation (SSF) system using oil palm leaves (OPL) as substrate was investigated. Fermentation parameters studied using one factor at a time (OFAT) technique, were carbon-nitrogen (C/N) ratio, mineral solution size and inoculums size. It was found that the optimum C/N ratio was at 0.4 with xylanase activity at 16.046 U/min. Meanwhile, the optimum size for both mineral solution size and inoculum size were at 1 ml with the xylanase activity recorded at 14.500 U/min and 19.057 U/min respectively. This shows that that the utilization of OPL as substrates in xylanase production using Aspergillus niger ATCC 16404 was a successful.

Abstract: Garcinia mangostana is found to contain many antioxidants especially in the pericarp. During extraction process, antioxidant stability and phenolic content in the Garcinia mangostana was depended on the temperature applied during drying process as well as the type of solvent used. Therefore, it is important to know the temperature and the most suitable solvent used in order to maintain the stability of antioxidant and total phenolic content in the Garcinia mangostana pericarp. The purpose of this study is focused on the effect of extraction solvent and drying temperature on the antioxidant stability and total phenolic content in Garcinia mangostana pericarp. Three (3) types of solvent used in the extraction process were methanol, ethanol and distilled water. The effect of thermal on antioxidant stability was investigated by drying the Garcinia mangostana pericarp at temperature of 50°C, 60°C and 70°C for 3 to 24 hours. From this study, it is found that the best solvent used for extraction was methanol and the best condition for drying temperature is at 55.13°C for 3 hours. Results from this study are important in Garcinia mangostana pericarp preservation, shelf-life, and improvements of the quality.

Abstract: Clay is the primary cause for resistivity reduction in most of the low resistivity pay cases. While dry clay acts as insulator, reaction with water made wet clay a good conductor. Clay conductivity is contributed by the exchangeable cation properties of the mineral. This reduces the actual resistivity of the formation, especially in the invaded zone. The effect is more severe if clay existed as dispersed type in the formation; which will also reduce other important petrophysical properties such as porosity and permeability. The study was conducted to observe the mechanism and reduction of formation resistivity due to mud invasion and find the relationship between resistivity reduction and petrophysical properties of the formation. The resistivity was measured on four types of samples with different grain size and sorting; well sorted fine grain size, well sorted medium grain size, well sorted coarse grain size and not well sorted sand. Three types of fluids were flushed into sand pack those are brine, crude oil and water based mud to simulate the invasion process. Sand pack with not well sorted sand and fine grain size had the most resistivity reduction, which possibly due to the high clay content that interacted with water.

Abstract: This study investigated the effect amount of maltodextrin as a carrier agent in production of Kaffir Lime powder. Pure concentrated Citrus Hystrix juice with maltodextrin as carrier agent has been spray dried at constant inlet temperature of 140°C, outlet temperatute of 70°C and pressure of 40psi and pump speeds at 1 rpm with different percentage of maltodextrin. The highest amount of Kaffir Lime powder, 23.43 g was obtained at 40% of maltodextrin added to the juice.

Abstract: The formations of bubble in the polystyrene latex (PSL) aqueous suspension were observed through out the electrophoretic deposition (EPD) process. The voltages in between of 20V to 50V were studied as a parameter for this study to investigate reason of bad quality of deposition when high voltage is applied in the EPD process. The objectives of the study are to observe the pattern and to determine of bubbles formation size on the stainless steel during pulse EPD process. The PSL suspension from pH 5 to 10 were prepared. The bubble formation was observed and size of bubbles was measured by using microscopic video. The difference voltages are applied on the suspension to observe the best condition with no or low bubbles formation when voltage applied. From the experiment, when the voltages increase, the number of bubbles increases. Observation shown that at low voltage the bubble tend to grow up and then burst during the process. As an addition, the sizes of bubbles decrease in base suspension though its increase in acid suspension.