257 research outputs found

    Methyl esters selectivity of transesterification reaction with homogenous alkaline catalyst to produce biodiesel in batch, plug flow, and continuous stirred tank reactors

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    Selectivity concept is essential in establishing the best operating conditions for attaining maximum production of the desired product. For complex reaction such as biodiesel fuel synthesis, kinetic studies of transesterification reaction have revealed the mechanism of the reaction and rate constants. The objectives of this research are to develop the kinetic parameters for determination of methyl esters and glycerol selectivity, evaluate the significance of the reverse reaction in transesterification reaction, and examine the influence of reaction characteristics (reaction temperature, methanol to oil molar ratio, and the amount of catalyst) on selectivity. For this study, published reaction rate constants of transesterification reaction were used to develop mathematical expressions for selectivities. In order to examine the base case and reversible transesterification, two calculation schemes (Case 1 and Case 2) were established. An enhanced selectivity was found in the base case of transesterification reaction. The selectivity was greatly improved at optimum reaction temperature (60 C), molar ratio (9 : 1), catalyst concentration (1.5 wt.%), and low free fatty acid feedstock. Further research might explore the application of selectivity for specifying reactor configurations

    Methyl esters selectivity of transesterification reaction with homogenous alkaline catalyst to produce biodiesel in batch, plug flow, and continuous stirred tank reactors

    Get PDF
    Selectivity concept is essential in establishing the best operating conditions for attaining maximum production of the desired product. For complex reaction such as biodiesel fuel synthesis, kinetic studies of transesterification reaction have revealed the mechanism of the reaction and rate constants. The objectives of this research are to develop the kinetic parameters for determination of methyl esters and glycerol selectivity, evaluate the significance of the reverse reaction in transesterification reaction, and examine the influence of reaction characteristics (reaction temperature, methanol to oil molar ratio, and the amount of catalyst) on selectivity. For this study, published reaction rate constants of transesterification reaction were used to develop mathematical expressions for selectivities. In order to examine the base case and reversible transesterification, two calculation schemes (Case 1 and Case 2) were established. An enhanced selectivity was found in the base case of transesterification reaction. The selectivity was greatly improved at optimum reaction temperature (60 C), molar ratio (9 : 1), catalyst concentration (1.5 wt.%), and low free fatty acid feedstock. Further research might explore the application of selectivity for specifying reactor configurations

    Respons Siswa Terhadap Sajian Simbol, Tabel, Grafik Dan Diagram Dalam Materi Logaritma Di SMA

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    This research aims to: (1) determine the students' response to the presentation of symbolic in logarithms in SMA Mujahidin Pontianak, (2) determine the students' responses to the presentation of table in logarithms in SMA Mujahidin Pontianak, (3) determine students' responses to the presentation of graphic in logarithms in SMA Mujahidin Pontianak, and (4) determine students' responses to the presentation of diagram in logarithms in SMA Mujahidin Pontianak. The subjects in this research are 68 students. The form of research is descriptive. The data collection of the students response is using questionnaires. The results of the data analysis showed that the grade X SMA Mujahidin Pontianak: (1) student response to the presentation of symbolic is 47.5% include to the Very Low category, (2) the response of students to the presentation of table is 70% include to the Moderate category, (3) response students to the presentation of graphic is 39.33% include to the Very Low category, and (4) the response of students to the presentation of diagram of 45.67% include to the Very Low category

    Harmonic reduction of a single-phase multilevel inverter using genetic algorithm and particle swarm optimization

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    Inverter play important role in power system especially with it capability on reducing system size and increase efficient. Recent research trend of power electronics system are focusing on multilevel inverter topic in optimization on voltage output, reduce total harmonics distortion, modulation technique and switching configuration. Standalone application multilevel inverter is high focused due to the rise of renewable energy policy all around the world. Hence, this research emphasis on identify best topology of multilevel inverter and optimize it among the diode-clamped, capacitor clamped and cascaded H-bridge multilevel inverter to be used for standalone application in term of total harmonics distortion and voltage boosting capability. The first part of research that is identify best topology multilevel inverter is applying sinusoidal pulse width modulation technique. The result shown cascade H-bridge give the best output in both total harmonics distortion (9.27%) and fundamental component voltage (240 Vrms). The research proceed with optimization with fundamental switching frequency method that is optimized harmonic stepped waveform modulation method. The selective harmonics elimination calculation have adapt with genetic algorithm and particle swarm optimization in order to speed up the calculation. Both bio-inspired algorithm is compared in term of total harmonic distortion and selected harmonics elimination for both equal and unequal sources. In overall result shown both algorithm have high accuracy in solving the non-linear equation. However, genetic algorithm shown better output quality in term of selected harmonics elimination where overall no exceeding 0.4%. Particle swarm optimization shows strength in finding best total harmonics distortion where in 7-level cascaded H-bridge multilevel inverter (m=0.8) show 6.8% only as compared to genetic algorithm. Simulation for 3-level, 5-level and 7-level for each multilevel inverter at different circumferences had been done in this research. The result draw out a conclusion where the possibility of having a filterless high efficient invert can be achieve

    CO2 removal using amine-functionalized kenaf in pressure swing adsorption system

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    An agro-based adsorbent from kenaf (Hibiscus cannabinus L.) for CO2 removal was prepared by functionalizing it with amine. Amine functionalization improves the adsorbates–adsorbent interaction through the presence of basic active sites on the adsorbent surfaces. Several amines (MEA, DEA, MDEA, AMP, PEI, DETA, TETA, TEPA, DIPA, PEHA, TEA, and DGA) have been selected for the amine-screening process. The result revealed that adsorption capacity of raw kenaf is only 0.624 mmol/g, whereas TEPA attained the highest CO2 capture capacity (0.914 mmol/g). Further study on the effect of amine loadings was conducted using two types of amine (MEA and TEPA) and it was found that the highest CO2 adsorption capacity for is 2.070 mmol/g for MEA to kenaf ratio of 1:1 and 2.086 mmol/g for TEPA to kenaf ratio of 2:1. The regeneration study also showed that kenaf sorbent can be used for repeated cycle operations. Due to the presence of amine on kenaf, the regeneration values of MEA–kenaf (82.15%) and TEPA–kenaf (75.62%) were lower than the raw kenaf (99.07%)

    Evaluation of in vitro Vibrio static activity of Shewanella algae isolated from healthy Penaeus monodon

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    To conquer disease problem in shrimp industries, probiotic biocontrol is a well known remedy now. The antagonistic ability of separated isolates from different parts of juvenile Penaeus monodon werescreened against shrimp Vibrio pathogens; Vibrio parahaemolyticus and Vibrio alginolyticus. The most antagonistic effect was observed for an isolate that was primarily identified as Shewanella algae usingconventional methods followed by Biolog microlog software. Since production of antagonistic agents rely on cultural conditions, antagonistic ability of candidate probioic against the mentioned Vibrios was assessed using Response Surface Methodology, with central composite design in which four independents variables were assumed: temperature (10 - 50°C), pH (6 -10), NaCl concentration (0 - 50%)and time (12 – 60 h). The coefficients of multiple determinations (R2), for the responses of antagonistic effect of S. algae against V. parahaemolyticus and V. alginolyticus values were 0.807 and 0.805,respectively. Concentration of the NaCl exhibited least influence on the antibacterial effect of candidate probiotic while the other independent variables exhibited different degree of affect. The candidateprobiotic revealed a reasonable antibacterial response in quite a wide range of temperature and pH in which the maximum levels were in the same range of optimum shrimp culture

    Selection of classification models from repository of model for water quality dataset

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    This paper proposes a new technique, Model Selection Technique (MST) for selection andranking of models from the repository of models by combining three performance measures(Acc, TPR and TNR). This technique provides weightage to each performance measure to findthe most suitable model from the repository of models. A number of classification modelshave been generated to classify water quality using the most significant features andclassifiers such as J48, JRip and BayesNet. To validate this technique proposed, the waterquality dataset of Kinta River was used in this research. The results demonstrate that theFunction classifier is the optimal model with the most outstanding accuracy of 97.02%, TPR =0.96 and TNR = 0.98. In conclusion, MST is able to find the most relevant model from therepository of models by using weights in classifying the water quality dataset.Keywords: selection of models; water quality; classification model; models repository

    Elucidating the Surface Functionality of Biomimetic RGD Peptides Immobilized on Nano-P(3HB-co-4HB) for H9c2 Myoblast Cell Proliferation

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    Biomaterial scaffolds play crucial role to promote cell proliferation and foster the regeneration of new tissues. The progress in material science has paved the way for the generation of ingenious biomaterials. However, these biomaterials require further optimization to be effectively used in existing clinical treatments. It is crucial to develop biomaterials which mimics structure that can be actively involved in delivering signals to cells for the formation of the regenerated tissue. In this research we nanoengineered a functional scaffold to support the proliferation of myoblast cells. Poly(3-hydroxybutyrate-co-4-hydroxybutyrate) [P(3HB-co-4HB)] copolymer is chosen as scaffold material owing to its desirable mechanical and physical properties combined with good biocompatibility, thus eliciting appropriate host tissue responses. In this study P(3HB-co-4HB) copolymer was biosynthesized using Cupriavidus malaysiensis USMAA1020 transformant harboring additional PHA synthase gene, and the viability of a novel P(3HB-co-4HB) electrospun nanofiber scaffold, surface functionalized with RGD peptides, was explored. In order to immobilize RGD peptides molecules onto the P(3HB-co-4HB) nanofibers surface, an aminolysis reaction was performed. The nanoengineered scaffolds were characterized using SEM, organic elemental analysis (CHN analysis), FTIR, surface wettability and their in vitro degradation behavior was evaluated. The cell culture study using H9c2 myoblast cells was conducted to assess the in vitro cellular response of the engineered scaffold. Our results demonstrated that nano-P(3HB-co-4HB)-RGD scaffold possessed an average fiber diameter distribution between 200 and 300 nm, closely biomimicking, from a morphological point of view, the structural ECM components, thus acting as potential ECM analogs. This study indicates that the surface conjugation of biomimetic RGD peptide to the nano-P(3HB-co-4HB) fibers increased the surface wettability (15 ± 2°) and enhanced H9c2 myoblast cells attachment and proliferation. In summary, the study reveals that nano-P(3HB-co-4HB)-RGD scaffold can be considered a promising candidate to be further explored as cardiac construct for building cardiac construct

    A study of frequency and pulses for stepper motor controller system by using programmable logic controller

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    The stepper motor movement process produced different frequency and pulses. This research explained about the frequency and pulses for the stepper motor movement by using Programmable Logic Controller (PLC) as research method. The study was done to find the suitable frequency and pulses for stepper motor movement by developing a prototype stepper motor controller system. The pulse frequency used did not affected the distance of moving load in the stepper motor operations. The increasing number of pulse frequency only will affect the time taken for the stepper motor to complete its operations. The result showed that number of pulse frequency at high operation was 5000 Hz. Pulse number reacted as a manipulated variable that affected both factor which is time taken of stepper motor operation and the distance of moving load
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