Synthesis and optimization ring opening of monoepoxide linoleic acid using p-toluenesulfonic acid

Biolubricant base oils, 9,12-hydroxy-10,13-oleioxy-12-octadecanoic acid (HYOOA) was synthesized based on the esterification reaction of Monoepoxide linoleic acid 9(12)-10(13)-monoepoxy 12(9)-octadecanoic acid (MEOA) with oleic acid (OA) and catalyzed by p-Toluenesulfonic acid. The optimum conditions for the experiment using D-optimal design to obtain high yield% of 84.61, conversion% of 83.54 and lowest OOC% of 0.05 were predicted at OA/MEOA ratio of 0.2:1 (mol/mol), PTSA/MEOA ratio of 0.4:1 (mol/mol), reaction temperature at 110°C, and reaction time at 4.5 h. The FTIR peaks of HYOOA indicate the disappearance of the absorption band at 820 cm(−1), which belongs to the oxirane ring. (13)C and (1)H NMR spectra analyses confirmed the result of HYOOA with appearance carbon-ester (C = O) chemical shift at 174.1 ppm and at 4.06 ppm for (13)C and (1)H NMR respectively

Refinement of SOR method for the rational finite difference solution of first-order fredholm integro-differential equations

As it is known, the linear rational finite difference (LRFD) method has the advantage of its excellent stability, and the Successive Over-Relaxation (SOR) method has the advantage of fast convergence rate due to the flexible choice of parameter. In this paper, in order to make full use of the advantages of LRFD and SOR methods, the composite trapezoidal (CT) quadrature scheme is combined with the 3-point linear rational finite difference (3LRFD) method (CT-3LRFD) to discretize the first-order linear Fredholm integro-differential equation and produce the approximation equation. Furthermore, the SOR method is extended to be the refinement of Successive Over-Relaxation (RSOR) method which then used to solve the numerical solution of the generated linear systems. At the same time, for the sake of comparison, the classical Gauss-Seidel (GS) and Successive Over-Relaxation (SOR) methods are also introduced as the control method. In the end, through several numerical examples, the three parameters of the number of iterations, the execution time and the maximum absolute error are displayed, which fully illustrate that the RSOR method is competitive with existing GS and SOR methods in solving large dense linear system generated by the CT-3LRFD formula

Fatty acid composition and physicochemical properties of Malaysian castor bean Ricinus communis L. seed oil

The crude oil of Malaysian castor bean Ricinus communis L. seed was extracted by Soxhlet method using hexane. The physicochemical characteristics of castor bean oil were evaluated. The results showed that Malaysian castor seeds contain a relatively high percentage of total lipids content; 43.3% (per dry weight), high iodine value (84.5 mg/g) and saponification value (182.96 mg/g). The seed oil moisture content, acid value and free fatty acid percentage (% FFA) were 0.2%, 4.88 mg/g and 3.4%, respectively. The unsaturated fatty acids (UFA) content were 97.5% of the total fatty acids composition. Ricinoleic acid comprises over 84% while other fatty acids present were linoleic (7.3%), oleic (5.5%), palmitic (1.3%), stearic (1.2%) and linolenic (0.5%), respectively. Five types of castor bean seed oil triacylglycerols were identified as triricinolein, RRR (84.1%), diricinoleoylstearoylglycerol, RRS (8.2%), diricinoleoyloleoyl-glycerol, RRO (5.6%), diricinoleoyllinoleoylglycerol, RRL (1.2%) and diricinoleoylpalmitoyl-glycerol, RRP (0.9%), respectively

Linear rational finite difference solution for solving first-order fredholm integro-differential equations

In this paper, we deal with the application of the linear rational finite difference (LRFD) method together with the first-order quadrature scheme to derive the first-order quadrature-rational finite difference approximation equation for first-order linear Fredholm integro-differential equations (FIDE). Derivation of this approximation equation, the linear system can be generated in which its coefficient matrix is large and dense. To make a comparison, the classical finite difference method (FD) based on the second-order central difference scheme is also presented. In numerical experiments, the maximum values of absolute errors of the numerical solutions obtained by both methods have been compared. Therefore, it can be concluded that the accuracy of numerical solutions for the quadrature-LRFD gives more accurate than the quadrature-FD method

The performance of alternating top-bottom strategy for successive over relaxation scheme on two dimensional boundary value problem

This paper present the implementation of a new ordering strategy on Successive Overrelaxation scheme on two dimensional boundary value problems. The strategy involve two directions alternatingly; from top and bottom of the solution domain. The method shows to significantly reduce the iteration number to converge. Four numerical experiments were carried out to examine the performance of the new strategy

Successive over relaxation method in solving two-point fuzzy boundary value problems

In this study, numerical methods are considered in solving the fuzzy boundary value problem (FBVP). This boundary value problem will then be discretized to derive second order finite difference equation and hence generated fuzzy linear system. The approximation solver towards system of linear equations is described through the implementation of the Gauss-Seidel (GS) and Successive Over Relaxation (SOR) iterative methods. Then several numerical experiments were shown to illustrate the effectiveness of SOR iterative method compared with the GS method

Numerical solutions of nonlinear second-order two-point boundary value problems using half-sweep SOR with Newton Method

In this paper, we examine the performance of Half-Sweep Successive Over-Relaxation (HSSOR) iterative method together with Newton scheme namely Newton-HSSOR in solving the nonlinear systems generated from second order finite difference discretization of the nonlinear second-order two-point boundary value problems. As well known that to linearize nonlinear systems, the Newton scheme has been used to transform the nonlinear system into the form of linear system. Then the basic formulation and implementation of Newton-HSSOR iterative method are also presented. Numerical results for three test examples have demonstrated the performance of Newton-HSSOR method compared to other existing SOR methods

Effectiveness the drying time and kinetic of seaweed kappaphycus alvarezii var. Tambalang in green v-roof hybrid solar drier

The solar drying experiment of seaweed using Green V-Roof Hybrid Solar Drier (GVRHSD) was conducted in Semporna, Sabah under the metrological condition in Malaysia. Drying of sample seaweed in GVRHSD reduced the moisture content from about 90.50% to 38% in 4 days at average solar radiation of about 600W/m2 and mass flow rate about 0.05 kg/s. The drying kinetics were fitted with ten published exponential model thin layer drying models. The models were fitted using the coefficient of determination (R2), and root mean square error (RMSE).The modeling of models using raw data be tested with the possible of exponential drying method. The result showed that the model from modified Page was found to the best model for describe the drying behavior. The R2 and RSME values for the best model was 0.9989 and 0.0497 respectively