Optimization of Ultrasonic Assisted Extraction Process on Antioxidant Activity of Honje Fruit Extract (Etlingera elatior) Using Surface Response Method

Honje fruit (Etlingera elatior) contains bioactive compounds as antioxidants. An antioxidant can be obtained by extraction. This research aimed to determine the best combination of solvent amount and extraction time to produce the optimal yield and antioxidant activity. The extraction method was UAE (Ultrasound Assisted Extraction) using ethanol 96% solvent amount 125 mL to 250 mL and time level of 30 to 60 minutes. The RSM (Response Surface Methodology) in the Design Expert 11 application was used to arrange the extraction combination treatment, which resulted in 13 runs. Parameters analyzed were total yield, antioxidant activity, pH, specific gravity, and color. The results showed that total yield was revealed quadratic, Y1 = 19.05 – 1.76A + 0.32B – 0.002AB + 0.023A2 – 0.0005B2 and the antioxidant activity was revealed linear, Y2 = 408.147 – 6.424A + 0.326B. The optimum treatment was achieved in the amount of solvent 174.815 ml and extraction time of 60 minutes resulted in a total yield of 17.125% and antioxidant activity of 77.55 ppm that could be classified as strong.

Response Surface Regression with LTS and MM-Estimator to Overcome Outliers on Red Roselle Flowers

The surface response method is similar to the regression analysis method which uses procedures or ways of estimating the response function regression model based on the Ordinary Least Square (OLS) method. Unfortunately, using the quadratic method has no drawbacks because it is easily sensitive to assumption deviations due to outlier cases. One of the solutions to the outlier problem is using robust regression. The method of parameters in the regression is very diverse, but the methods used in this study are the Least Trimmed Square (LTS) and MM-estimator methods because both methods have a high breakdown point of nearly 50%. The variables studied were the response variable consisting of red roselle plant height (Y1) and red roselle flower weight (Y2). While the independent variables were soil moisture factor (X1) and NPK fertilizer application factor (X2). The purpose of this study is to estimate the response surface regression parameters. using the LTS and MM-estimator methods on data that contains outliers. The resulting model in data analysis shows the same result that the best model is using the LTS estimation method. The modeling result of plant height obtained an R-Square value of 98,27% with an error is 1,243. Meanwhile, for the red rosella plant flower weight model, the R-Square value was 97,31% with an error is 0.6632.

Optimizing Edible Film from Corn Cobs with Surface Response Method

The increase in plastic production worldwide has created quite a serious environmental problem. Edible film is an alternative packaging that can decompose naturally, one of the materials that can be used to make edible films is starch. This study aims to determine the composition of corn cob starch and plasticizers that can produce edible films with the best properties. The starch used is derived from corn cobs and the plasticizers used are glycerol and sorbitol. The edible film in this study was made by the casting method by dispersing the raw materials, heating the mixture, printing the edible film and drying the edible film. This research was conducted with variations in the corncob of 5, 6 and 7 in grams and the variation of the ratio of glycerol to sorbitol plasticizer is 2:8; 3:7; 5:5; 7:3; 8:2 (ml). The more starch content increases the thickness of the edible film and tensile strength, but the elongation and water vapor permeability decreases, the best edible film is obtained at the glycerol-sorbitol composition ratio of 5:5 with the amount of corncob starch of 7 grams.

Optimization of the Alcoholic Concentration Obtained From Sugary Cassava (Manihot esculenta Crantz) by Response Surface Methodology

Sugary cassava or mandiocaba is a cassava variety of potential use for bioethanol production. In this study, laboratory-scale fermentations were carried out in a bioreactor with a working volume of 1L, using the yeast strain LNF CAT-1. A central composite design (CCD) was applied to determine the extent to which pH, temperature, and yeast concentration influence ethanol production with the aim of improving the fermentation process. The individual effects and the interaction of these factors were analyzed using a surface response method. Physicochemical properties of the material were also investigated and the analysis of root characterization showed high moisture content (~91%) and a low amount of starch (~4.0%), ash values close to 1.0%, total fibers 0.4%, proteins 0.15%, and lipids 0.1%. The results obtained from the wort presented a low acidity (~0.2%), pH close to neutrality (~6.5%), total soluble solids values of ~5.8%, glucose content ~2.3%, fructose ~1.0%, and sucrose ~1.2%. The second-order polynomial regression model determined that the maximum ethanol production of 2.8% (v/v) would be obtained when the optimum pH, temperature, and yeast concentration were ~5.0, 32-36 ºC, and ~10-14 g L-1, respectively.

Preparation and optimization of the composition of novel nZVI/(Fe-Mn) binary oxide/bentonite adsorbent for removal of reactive yellow 145 dye (RY-145) from aqueous solution

In this study, a new composite of nZVI/ (Fe - Mn) binary oxide/bentonite (IFMB) was synthesized and used as an adsorbent for the removal of reactive yellow 145 dye (RY- 145) from aqueous solution. Optimization of composition of IFMB composite for removal of RY - 145 dye was conducted with the help of surface response method (SRM). Three independent variables affecting to the RY-145 adsorption efficiency were selected for optimization study: Fe/Mn ratio (mol/mol), Bentonite content (wt. %) and nZVI content (wt. %). The study reveals that optimal compositions of IFMB composite for RY-145 removal was Fe/Mn = 1,75; Bentonite 9,46 wt. % and nZVI 16,97 wt. %. In the adsorption condition: adsorbent dose of 1g.L-1, initial dye concentration of 200 mg.L-1, contact time of 120 min at 120 rpm and at 25 oC, the adsorption capacity for RY-145 dye on IMFB composite is 197 mg.g-1. The value of RY-145 adsorption efficiency calculated by the model at the optimal point has been compared with the experimental value and the error is very small (0,36%). This proves that the RSM model has good repeatability.

Optimizing the Mercerisation Effect on the Mode I Fracture Toughness of Bambusa Vulgaris Bamboo Using Surface Response Method

Alkaline treatment is widely being promoted to treat natural fibres and improves the fibre bundle surface for better interlocking with the polymer matrix. The aim of this study is to optimize the merceration parameter including natrium hydroxide (NaOH) concentration, soaking and drying time for Bambusa Vulgaris bamboo using response surface methodology (RSM). Here, the treatment conditions were employed by the Box-Behnken design (BBD). The comparative study of the treated and untreated fibre on crack propagation behaviour, Mode I interlaminar fracture toughness (GIC) of the bamboo along the longitudinal direction test was carried out. Through the statistical analysis approach (ANOVA), it is suggested that bamboo treated with 1.5 wt.% concentration of NaOH is capable to reach the fracture toughness value up to 367.25 J/m2. It is also shown that all proposed variables for treatment in this study (i.e., the concentration of the NaOH is highly significant with the 2.85 hours of soaking and drying for 72.5 hours).

Analisis Ketebalan Lapisan pada Pengecatan Baja Karbon Rendah menggunakan Metode Respons Permukaan

The number of vehicles has increased every year. This increase was accompanied by an increase in the number of accidents that occurred. Accidents that occur result in damage to vehicles so that repainting is needed. Painting is an effort made by applying paint in liquid form on the surface of an object to create a layer on the surface of the object. Painting serves to protect and improve the appearance of a surface. The purpose of this study is to determine the effect of a combination of parameters that can produce maximum thickness values. The experimental design used in this study is a surface response method with three parameters where each parameter has three levels. The parameters chosen were spraying distance (110 mm, 130 mm, 150 mm), composition between paint-thinner (1/1.6, 1/1.4, 1/1.2), and pressure (3.5, 4.5, 5.5). The painting process is carried out with the help of a paint test demonstrator. The painting results are dried in the oven and then measured using a thickness gauge. The measurement data is processed using the help of Minitab software and the estimator equation for thickness is obtained. The parameters with the greatest influence in this study are the distance of spraying with a distance coefficient of 2.258. Painting with the highest average value of thickness occurred in the fifteenth experiment with a thickness value of 39.9 micron. The thickness is obtained by variable variations of 130 mm distance, paint-thinner 1/1.4 composition and 4.5 bar pressure.