This study is conducted to explore and utilize fresh mangosteen peel as an upcoming raw material for the production of natural dyes. The extract of fresh mangosteen peel is tested on cotton fabric by using alum as a mordanting agent who processed by pre-mordant dyeing procedure and fixation using 3 (three) different types of fixer. To obtain optimum interaction of fabric, mordant, dye and fixer, washing procedure has been performed using Turkish Red Oil (TRO) before the mordanting stage with varying washing time and repeated dyeing procedure with varying frequency of dyeing. As a result, the application of pre-mordanting dyeing method and fixation using iron (II) sulfate (FeSO 4 .7H 2 O), alum (KAI (SO 4) 2 .12H 2 O) and lime (CaO), produced very good color from mangosteen peel dyes extract. Cotton fabric that has been through the pre-mordanting dyeing procedure using dyes extract of mangosteen peel consecutively bring green, light brown, and dark brown color each on the fixation result using iron (II) sulfate, alum, and lime. Preliminary evaluation and instrumentation allow us to determine whether the application of washing time varies, the repeated frequency of immersion and the use of different fixers compound using dyes extract with similar concentration and dyeing procedure affect the color intensity of the fabric sample.

This study aims to analyze the differences in the effectiveness of the Jigsaw cooperative learning model and the direct learning model of student learning outcomes in DKB subjects in class X DPIB of Vocational High School 2 Surakarta; to analyze the differences in learning outcomes between students who have high critical thinking skills and students who have low critical thinking skills in DKB subjects in class X DPIB Vocational High School 2 Surakarta; and to analyze whether there is an interaction between the learning model and students' critical thinking skills towards student learning outcomes in the class X DKB DPIB Vocational High School 2 Surakarta. This study is a quantitative experimental study with a 2x2 factorial design. The sample of this study was the tenth grade students of DPIB Vocational High School 2 Surakarta in the 2018/2019 academic year, totaling 64 students. Data obtained from the results of observations, interviews, and tests. The data analysis technique uses 2-way Anava technique. The results is study's learning using Jigsaw cooperative learning model obtain the results of cognitive learning higher significant than learning outcomes cognitive students learn by using direct learning model on the subjects of DKB in Vocational High School 2 Surakarta; cognitive learning outcomes for students who have critical thinking skills height significantly higher than the results of cognitive learning students who have the skills to think critically low on the subjects of DKB in Vocational High School 2 Surakarta; and there is a very significant interaction between the learning model and the skill level which is critical to the cognitive learning outcomes of students in the DKB subjects at Vocational High School 2 Surakarta.

On this study has been conducted product standardization of ginger and red ginger simplicias as one of post-harvest processed form. To get ginger and red ginger simplicia product with high quality, has been done the optimization on the stage of washing, slicing, and drying process. Optimization has done in a range of 1-3 minutes washing time and raw material sliced thickness of 0.15 cm and 0.30 cm. In addition, the production of the entire simplicia has done with three drying methods, including sundried, sunlight through the intermediary of black fabric and dried by the oven. Specifically for the dried by the oven, has conducted optimization on the drying temperatures of 70° C; 85° C; 100˚C; and 115˚C. The analysis results of active compound content in the simplicia product indicates that the product of ginger and red ginger simplicia with optimum quality has obtained from the production process by washing time for 1 minute, slicing thickness of 0.15 cm, and oven drying method using temperature of 115° C. The ginger and red ginger simplicia product with optimum active compound content obtained by drying time, each for 310 minutes and 280 minutes. The ginger simplicia products contain essential oils, oleoresins, zingiberene in essential oils, gingerol and shogaol in the oleoresins, each by 1.7%; 0.86%; 56.90%; 42.50%; and 21.54%. Meanwhile, the red ginger simplicia products contain essential oils, oleoresins, zingiberene in essential oils, gingerol and shogaol in the oleoresins, each by 2.11%; 0.88%; 78.60%; 80.06%; and 8.02%. Thus, it can be said that, overall, red ginger simplicia product contains an active compound higher than the ginger simplicia product.

The potential of dye-sensitized solar cells (DSSC) as an alternative to depleting fossil fuels has been investigated. To optimize performance and efficiency, the effectiveness of PVDF and PVDF nanofiber (NF) membrane-based electrolytes in suppressing solvent leakage and evaporation in liquid electrolyte systems was evaluated. SEM results for PVDF NF membranes showed the formation of a network with a three-dimensional structure with a diameter of 100–300 nm and an average thickness of 0.14 mm. The Infrared (IR) spectrum shows the electrolyte and polymer-PVDF interactions. Differential Scanning Calorimetry (DSC) curve shows the melting transition of PVDF NF 7.66% lower than PVDF. Efficiency and resistance of DSSC based on natural dyes as measured by multimeter and Electrochemical Impedance Spectroscopy (EIS) at a solar intensity of 100 mW/cm2 showed the highest efficiency of anthocyanin-based DSSC from telang (Clitoria ternatea L.) flower extract. Its use as a photosensitizer in an electrolyte system based on PVDF NF membranes resulted in an efficiency that was not significantly different from that of liquid electrolytes (1.69%).

The asymmetric polysulfone/polyvinylidene fluoride composite membranes with vary polyvinylidene fluoride levels in coating dope were prepared by non-solvent induced phase separation. N-methyl pyrrolidinone and distilled-water were used as a combination of solvent and non-solvent, while ammonium chloride was applied as a porogenic additive in the system. Physical characteristics of the prepared membranes were analyzed using a scanning electron microscope. The membranes performance was analyzed in term of pure water flux, porosity, mechanical properties respectively. Results showed a good interaction between polyvinylidene fluoride material and polysulfone matrix. The polyvinylidene fluoride coating on the polysulfone matrix has increased the small pore quantity in the skin layer and strengthened the mechanical strength of the membrane. In addition, increased porosity with increasing doses of polyvinylidene fluoride in the dope solution does not necessarily increase the pure water flux of the membranes.