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"This study was aimed todetermine the reaction stoichiometry between Cu(II) and di-2-ethylhexylphosphoricacid (D2EHPA) in Waste Palm CookingOil (WPCO). The stoichiometry was computed based onthe followingexperimentalmethods, namely slope analysis, loading test and Job?smethod. Slope analysis was used to measure the variation of the distribution coefficient"

"This study was aimed to determine the reaction stoichiometry between Cu(II) and di-2-ethylhexylphosphoric acid (D2EHPA) in Waste Palm Cooking Oil (WPCO). The stoichiometry was computed based on the following experimental methods, namely slope analysis, loading test and Job’s method. Slope analysis was used to measure the variation of the distribution coefficient D to the concentration of Cu(II) ions and D2EHPA. Besides that, the loading test and Job’s method are used to determine and confirm the complexation reaction between D2EHPA and Cu(II) ions. It was found that, the reaction stoichiometry for the Cu(II) to D2EHPA was 1:2 in Cu(II) organic complexes. Therefore, the chemical equation can be determined and it will be a useful information in the reaction mechanism of Cu(II) with D2EHPA in WPCO."

"The combination ofbaffled air flotation and a membrane system for the treatment of palm oil milleffluent (POME) was studied. The POME was obtained from a palm oil factory inPTPN I Tanjong Seumantoh, Aceh, Indonesia. Operation variables and conditions,such as the hydraulic retention time and air flow rates, were varied to findthe optimum process. The air flotation process is able to reduce theconcentration of suspended solids and fats/ oils contained in the wastewater,which increases the performance of the membrane by reducing clogging. Theresults showed that this method was promising for POME treatment. The optimumorganic removal efficiency of the air flotation pretreatment was obtained atHRT = 5 days and at an air flow rate of 11 L/min. The effluent was subsequentlypassed through an anaerobic membrane system to achieve the highest removalefficiency treatment. The removal efficiency of chemical oxygen demand (COD),total suspended solids (TSS), turbidity, mixed liquor suspended solids (MLSS),mixed liquor volatile suspended solids (MLVSS), and fats/oils after passingthrough the membrane system were 97%, 93.9%, 99.8%, 94.5%, 96.2%, and 99.9%,respectively. The results also showed that the pH could be neutralized to 6.18,while a dissolved oxygen (DO) level of 1.60 mg/L could be achieved. A highquality of effluent was obtained, which met the standards for POME effluent."

"Oil palm empty fruit bunch (OPEFB) is one of the waste products of oil palm plantations and has not been optimally used in Riau Province, Sumatera, Indonesia. OPEFB is reduced by incineration, which causes pollution problems. However, the combustion of OPEFB generates ash, which is rich in potassium. Moreover, OPEFB fiber has good strength, low cost, low density, and biodegradability, and it can be used as composite reinforcement. However, the natural fibers in composites have poor compatibility with the matrix and relatively high moisture absorption. Hydrolysis of OPEFB ash creates a base solution that can be utilized in an alkaline treatment process to increase the mechanical properties of natural composites.The aim of this study was to investigate the effect of various extracts of OPEFB ash on the tensile strength, flexural strength, and water absorption of an OPEFB fiber-polypropylene composite. The experimental design used was the Response Surface Method-Central Composite Design (RSM-CCD). The results showed that the tensile strength increased with an increase of fiber length and concentration of the OPEFB ash extract solution, but tensile strength decreased with a longer soaking time. Flexural strength increased with an increase in fiber length but decreased with an increase in the concentration of the OPEFB ash extract solution and longer soaking time. Water absorption increased with lower and higher concentrations of OPEFB ash extract solution and fiber length and with shorter and longer soaking times. The highest tensile strength (20.100 MPa) was achieved at 5%wt alkaline concentration, 36 h soaking time, and 3 cm fiber length. The highest flexural strength (30.216 MPa) was achieved at 5%wt alkaline concentration, 12 h soaking time, and 3 cm fiber length. The lowest water absorption (0.324%) was achieved at 10%wt alkaline concentration, 24 h soaking time, and 2 cm fiber length."

"The research aims to scale up a small-scale stirred batch reactor to a large-scale stirred batch reactor in order to degum crude palm oil for use as a raw material in biodiesel production. The scale-up is based on the similarity of fluid Reynolds numbers in the two differently sized reactors. To achieve this aim, computational fluid dynamic modeling and simulations of the two reactors were performed. A small-scale palm oil degumming process was carried out in a 250 cc autoclave reactor using a magnetic stirrer at 500 rpm. The simulation results of this small reactor yielded a fluid Reynolds number in the range of 5 to 3,482. The large-scale reactor proposed in this research is 1.25 m3 in volume and is equipped with two impellers: a pitched blade impeller and a Rushton turbine impeller. The pitched blade impeller is placed over the Rushton turbine impeller. They are rotated at 100 rpm. Under this setting and operation, the resulting fluid Reynolds number was in the range of 486 to 202,000. This result indicates that the large-scale reactor was able to reproduce the reaction performance obtained in the small-scale reactor."

"Vanadium-doped LiFePO4/Cused as a cathode for a lithium ion battery has been successfully synthesized.In this work, LiFePO4 was synthesized from LiOH, NH4H2PO4,and FeSO4.7H2O at a stoichiometric amount. Vanadium was added in theform of H4NO3V at concentration variations and 3 wt.%carbon black. The characterization includes thermal analysis, X-raydiffraction, electron microscopy, and electrical impedance spectroscopy. Thethermal analysis results showed that the LiFePO4 formationtemperature is 653.8?700.0°C. The X-raydiffraction results showed an olivine structure with an orthorhombic spacegroup, whereas the electron microscopy results showed that LiFePO4/Chas a round shape with an agglomerated microstructure. Electrical impedancetest results showed values of 158 Ω and 59 Ω for the as-synthesizedLiFePO4/C and the 5 wt.% vanadium-dopedLiFePO4/C, respectively. Cyclic performance test results at 1 Cshowed capacities of 24.0 mAh/g and 31.2 mAh/g for the as-synthesized LiFePO4/Cand the 5 wt.% vanadium-doped LiFePO4/C,respectively. Charge and discharge test results showed charge and dischargecapacities of 27.6 mAh/g and 40.2 mAh/g for the as-synthesized LiFePO4/Candthe5 wt.%vanadium-doped LiFePO4, respectively. This result is promisingin terms of increasing the performance of a lithium ion battery."

"Ballast is one of themain structures for the railway tracks. It can resist the lateral movementunder dynamic loading transferred by the passing trains with repeatedly. Undersome circumstances, ballast can suffer degradation or breakdown due to therepeated loading and maintenance. Ballast is easily exposed to the weatherbecause it is laid on the track. Acid rain affects the performance of therailway track near the industrial and urbanarea. As a result, it starts to foul and the small chips from ballast filledthe void, as well as reduce the shear strength of ballast particles. Thissituation can contribute into the increasing of maintenance frequency andcosting. This paper examines the potential of rubber inclusions in increasingthe shear resistance of rubber-ballast composites in simulated water and acid soakedconditions with several configuration. This lab-based exploratory work is only static load simulation in conventional shear boxsetup measuring 60 mm × 60 mm.The aggregates size is 10 times smaller than actual size of ballast. In orderto identify the shear resistance deterioration of rubber-aggregates mixtureunder poor drainage conditions by soaked a batch of aggregates in water andacid solution for 2 weeks to simulate accelerated weathering effects. The shearresistance did not rise dramatically with the rubber reinforcement. Thissusceptible shear strain plots indicate ductile behaviour on theaggregates-rubber composites. This is evident by the linear rise of shearstress with strain up to approximately 10% for the control samples (CS) untilit reaches a constant value. Note that all the specimens including CS are in aloose state during the testing because there were no tamping been applied onthe samples. Overall the circular patch (CP) specimen was the most favourablethan the other configurations. Both mechanisms contributed to the reducedoverall subsistence, accompanied by an increase in the shear resistance. Theinclusion of rubber elements apparently prevented the dilation of the granularmaterial when approaching the shear failure and the reducing the settlement."

"Inhibition is one of themechanisms used for mitigating the metallic corrosion, particularly in an acid environment. The present work aims toinvestigate theinhibiting effect of N-benzyl-N/-phenyl thiourea (BPTU) on thecorrosion of low carbon steel in a 0.1 M hydrochloric acid (HCl) solution using a Tafelextrapolation and linear polarization techniques. The study reveals that BPTUacts as an excellent anodic inhibitor for low carbon steel in a HClsolution. The protective efficiency of the compound was found to be more than97% even at higher temperatures. The study demonstrated that BPTU gets adsorbedon the steel surface, following Temkin?s adsorption isotherm and the inhibitionis controlled by a chemisorptionmechanism. The investigation shows that the results obtained from the Tafelextrapolation and linear polarization techniques for the corrosion of mildsteel in HCl medium were in good agreement. The influence of temperatures andconcentrations of BPTU on the corrosion of low carbon steel are alsoexamined in the present work."

"Batik waste can increase water characteristics, such as turbidity, colorand total suspended solids (TSS). Thus, an efficient technique for separatingBatik from the liquid to decrease these characteristics is needed. The aim ofthe current study was to understand the results of flotation using electrolysisand to investigate the bubble characteristics that influence the results of theflotation of Batik waste. Flotation studies have been conducted usingelectrolysis to produce bubbles to separate batik synthetic dye from theliquid. Research conducted with 316L stainless steel electrodes, inside a 100cm tall acrylic pipe with an inner diameter of 8.4 cm and a voltage variationof 10, 15 and 20 V. Batik waste was mixed with distilled water. Commercial alumpowder [aluminum sulfate, Al2(SO4)3.14H2O,that is 17% Al2O3] as the reagent was added to coagulateBatik waste in a ratio of 1 gram per 10 ml of Batik waste. The results showedthat flotation of Batik waste can be used to separate Batik waste with theaddition of alum. Alum was shown to be capable of acting as a collector in thistype of waste separation. The results showed that flotation using electrolysiscould be an effective method for reducing turbidity, color and TSS."

"Commercialization ofbioethanol has recently intensified due to its market stability, low cost,sustainability, alternative fuel energy composition, greener output andcolossal fossil fuel depletion. Recently, because of greenhouse intensityworldwide, many researches are ongoing to reprocess the waste as well asturning down the environmental pollution. With this scenario, the invention ofbioethanol was hailed as a great accomplishment to transform waste biomass tofuel energy and in turn reduce the massive usages of fossil fuels. In thisstudy, our review enlightens various sources of plant-based waste feed stocksas the raw materials for bioethanol production because they do not adverselyimpact the human food chain. However, the cheapest and conventionalfermentation method, yeast fermentation is also emphasized here notably forwaste biomass-to-bioethanol conversion. Since the key fermenting agent, yeastis readily available in local and international markets, it is morecost-effective in comparison with other fermentation agents. Furthermore, yeasthas genuine natural fermentation capability biologically and it produces zerochemical waste. This review also concerns a detailed overview of the biologicalconversion processes of lignocellulosic waste biomass-to-bioethanol, thediverse performance of different types of yeasts and yeast strains,plusbioreactor design, growth kinetics of yeast fermentation, environmentalissues, integrated usages on modern engines and motor vehicles, as well asfuture process development planning with some novel co-products."