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This study aimed to determine the difference between learning with the Discovery Learning and Make a Match (DL-MaM) learning model with the conventional model on learning achievement in the domain of knowledge and attitudes in the nomenclature of simple chemical compounds. The population of this study was all students of class X MIPA MAN 4 Sleman with a total of 6 classes. The research sample is taken in as many as two classes: class X MIPA 3 as the treatment class and class X MIPA 1 as the control class. The sampling technique is carried out by purposive sampling. The instruments used in this study consisted of three: (1) test instruments in the form of post-test questions to measure learning achievement in the domain of knowledge, (2) non-test instruments in the form of questionnaires to measure learning achievement in the domain of attitudes. The analysis technique uses parametric statistics (Independent Sample T-Test) to analyze learning achievement data in the knowledge domain and non-parametric (Mann-Whitney) to analyze learning achievement data in the attitude domain. Based on the results of the study, it can be concluded that there are significant differences in the use of DL-MaM student achievement in the domain of knowledge, and there is no significant difference in the use of DL-MaM on students' achievement in the domain of attitudes. [ABSTRACT FROM AUTHOR]

This study was to distinguish students' learning achievement of knowledge aspect and attitude aspects between the implementation of AIR learning model and expository learning on the buffer solution material. This research is an experimental research using quasi-experimental design, namely post-test only with non-equivalent group design. The research sample is all students of two classes at SMA Muhammadiyah Boarding School (MBS) for the 2019/2020 academic year as many as 68 students. Determination of this research sample using the purposive sampling method. The data analysis technique in this study used an independent sample t-test on the knowledge aspect and the attitude aspect of the students. The result of this study is, there is a significant difference in the learning achievement of the knowledge aspect and there is no significant difference in learning achievement in the attitude aspect of students between the implementation of the Auditory Intellectually Repetition (AIR) learning model and the expository learning model on the buffer solution material [ABSTRACT FROM AUTHOR]

Research on the effects of KMnO4 concentration as a catholyte on Microbial Fuel Cell (MFC) has been carried by amounts of previous studies. This study aims to determine KMnO4 concentration effects to the electricity and BOD/COD parameters of tempe waste pottery-based MFC. This study used dual-chamber MFC with pottery proton exchange membrane, tempe waste, and KMnO4 solutions varied from 0.1 M, 0.15 M, and 0.2 M. The MFC reactors were run in 48 hours with electricity measurement per 2 hours. The performance parameters are voltage (V), current (mA), and power density (mW/m2), Chemical Oxygen Demand (COD), and Biochemical Oxygen Demand (BOD). The highest power density was obtained at the concentration of 0.15 M of 950.3185 mW/m2, while the highest BOD and COD decreases were obtained at the concentration of 0.2 M of 96.28% and 68.26% for BOD and COD, respectively. [ABSTRACT FROM AUTHOR]

The development of polymer recycling is supported by research of degradation kinetics, pyrolysis products, and even reaction mechanisms. In this research, non-isothermal kinetic methods were used to estimate activation energies and to select the best fitting reaction models for high-density polyethylene (HDPE), low-density polyethylene (LDPE), polypropylene (PP), and polystyrene (PS). Pyrolysis is thermal heating of materials without oxygen and conversion into gas, liquid, and solid products. To perform an optimum pyrolysis, the degradation kinetics of plastic materials need to be studied. Fourier Transform Infra-Red Spectroscopy (FTIR) was used for characterization of initial materials and Thermogravimetry (TGA) was used to determine the degradation kinetics. Based on the results of the TGA, the optimal degradation temperature for plastic and mixed waste was determined from 380 to 500°C for each selected material. The kinetic method used is Coats-Redfern. From the results of the analysis, the activation energy range for thermal decomposition is 200–300 kJ/mol. This can indicate the minimum energy necessary for the pyrolysis process. [ABSTRACT FROM AUTHOR]

Banana (Musa p.) waste is one of the potential raw materials for biogas production to supply energy needs in a rural area since its huge quantity of waste in Indonesia. The annual production of banana fruit is more than 7 million tons of which about 10% is wasted due to lack of quality, deterioration, and consumption pattern. Besides it may cause environmental problems, the waste is suitable for biogas production. This research was aimed to investigate its potential use to produce biogas for the rural areas throughout the country. Fraction of the fruit i.e. flesh and peels was subjected to mesophilic (30°C, 1 atm) anaerobic digestion at concentrations of 0.2%VS; 0.4; 0.6; and 0.2; 0.7; 1.2, respectively. Both fractions delivered effective biogas yield at lower concentration 0.2%VS at the highest value of 416 ml STP/g VS (48% degradability) and of 328 ml STP/g VS (36%), respectively. Evaluation of the biogas production based on Modified Gompertz Model resulted in Po(ml), µm(d−1), and λp(d) at a value of 5.49, 9,23, and 1.3, respectively. Based on the experimental result, a simple BIOGASCALC_UII program was developed to simulate the size of digester for processing a local source of banana waste. A flat-bottom and conical roof cylindrical digester at a diameter (m) and height (m) of 4.4, and 9.22, respectively can digest 1,000 tons of banana waste per day delivering a daily biogas production up to 69 m3 STP/day (61%CH4). It is concluded that valorization of the waste into biogas is the best choice to better the environment. [ABSTRACT FROM AUTHOR]

Verification method on determination of chemical oxygen demand (COD) in hospital wastewater with close reflux by UV-Vis spectrophotometry have been carried out. Verification method is used to determine the acceptability requirements in quality control at the Indonesian Nasional Standard (SNI 06-6989.2:2019). The testing parameters of verification method include linearity, limit of linearity (LOL), limit of detection (LOD), limit of quantification (LOQ), precision, and accuracy. Based on the calibration curve if the COD standard series has linearity in accordance with the standard with correlation coefficient (r) of 0.9975 and determination coefficient (R) of 0.9975. Determination of the limit of linearity (LoL) with degree of freedom, df1 =df2 = 9 and internal confidence level of 95% obtained F test = 0.3490 ≤ F table = 6.057 indicates that the calibration curve satisfies the linearity and is accepted as the calibration curve. The limit of detection (LOD) is 7.5779 mg/L, therefore the minimum COD value can be detected with significant response. The limit of quantification is 25.2596 mg/L which shows that the minimum COD value can be determined. This method has high precision with acceptability requirements with % RSD is 3.2205% and CV Horwitz is 4.1356%. The trueness percentage is 103.49% in accordance with acceptability quality requirements with the range 85 – 110 % indicating that this methods has high accuracy. [ABSTRACT FROM AUTHOR]

Removal of phenol and chlorophenol from aqueous solution by magnetic Fe3O4-CuO/biochar has been investigated. Bimetallic ions of iron and copper were immobilized on the surface of biochar prepared from the agricultural by product. Equilibrium adsorption of phenol and chlorophenol onto composite were evaluated using Langmuir dan Freundlich isotherms. Langmuir isotherm model for phenol and chlorophenol are more favorable model than that of Freundlich isotherm related to the monolayer. Adsorption kinetics for phenol and chlorophenol indicated pseudo-second-order with correlation coefficient closed to 1. the adsorption of phenol and chlorophenol are dependent on the adsorption parameter pH, concentration, contact time and weight of adsorbent. From the experiment data, it was observed that uptake of phenol is higher than chlorophenol. [ABSTRACT FROM AUTHOR]

Microplastics (MPs) assessment was conducted in five sites along Langkawi Island off Strait of Malacca coastal shoreline. In this paper, an improved protocol of digestion for soft tissue digestion and multi-steps of MPs identification had been developed and the polymer identification of MPs are performed by ATR-FTIR. Number of MPs found varied from 0.47 to 1.0 items/w. weight (g) and 0.73 to 1.47 items/individual of rock oysters. The MPs composition was dominated by threadlike shapes and the color found are black, blue, red, grey, and yellow. Size of MPs ranging between 500 to 1000 µm and based on MPs polymer analysis, polymers identified are PVDF, PP and PET. The overall abundancy of MPs in bivalve found in Langkawi is 1.46 ± 0.007 items/w. weight (g), however, it is still necessary to do periodic monitoring in this tourists' attraction island that is well-known for seafood. [ABSTRACT FROM AUTHOR]

This research has been carried out to compare complexometric titration methods and atomic absorption spectrophotometry in determining water hardness. The complexometric titration method has become the standard method of determining water hardness levels used in various references in several countries. The level of water hardness in several studies is known to be determined by atomic absorption spectrometry method. Both methods have good precision (%RSD ≤ 2%). Accuracy is calculated by repeatability system with the results of %recovery 92.57% for the titrimetric method and 106.99% for the spectrometric method. The results of the t-test for both methods stated that the t-count value (56.89) > t-table value (2.78). This shows that the two methods have significant differences. [ABSTRACT FROM AUTHOR]

Validation of the method of determining ascorbic acid by UV-Vis spectrophotometry in packaged drinks has been carried out with variations in the calibration curve range. The calibration curve was made into three variations, low range (between 0-3 ppm), medium range (between 0-20 ppm), and high range (between 0-25 ppm). The validation parameters analyzed were linearity, Limit of detection (LoD), Limit of Quantification (LoQ), precision, accuracy, and measurement uncertainty. The selection of the calibration curve range may affect the test results. The lowest linearity value is obtained in the low calibration curve range because some concentration points are lower than LOD. The value of precision and accuracy in the low range is also the lowest, while measurement uncertainty is the highest. This is because the sample concentration is outside the capacity of the calibration curve. Therefore, it is necessary to conduct a study related to the effect of the calibration curve on the method validation parameters before being used in testing, especially in laboratories that have received ISO 17025 accreditation. [ABSTRACT FROM AUTHOR]

Centella asiatica has been widely exploited in the cosmeceutical and pharmaceutical industries due to its biological properties, owing to the presence of asiaticoside. This study applied Soxhlet extraction method in extracting asiaticoside since this conventional method is easy to handle and acts as a reference method for new advanced methods. Also, the objective of this study is to determine the influence of the independent parameters namely, sample: solvent, solvent: co-solvent ratios, and extraction time to the yield of asiaticoside content. The effects of three independent parameters were analysed using Two-Level Factorial Design. The significance of the model was analysed using ANOVA analysis, which studied at p-value < 0.05. From Two-Level Factorial Design, the individual parameters namely sample: solvent, solvent: co-solvent ratios, and extraction time were insignificant to the asiaticoside content (p > 0.05). However, the interaction between factors; sample: solvent and solvent: co-solvent ratios exhibited a significant effect (p < 0.05) to the asiaticoside content. The optimal extraction condition suggested by Two-level Factorial were 1: 50, 100 %, and 7 hours for sample: solvent ratio, solvent, and extraction time, respectively. Hence, the suggested extraction conditions can be further applied in future research to extract asiaticoside from C. asiatica using Soxhlet extraction method. [ABSTRACT FROM AUTHOR]

This study aims to evaluate the effects of solvents extraction and drying methods on selected fucoxanthin content in Sargassum polycystum that was collected from Blue Lagoon, Port Dickson Malaysia. Two different drying methods were used in this study, i.e sun-drying and air-drying. Acetone, methanol and ethanol were used as the solvents to extract the fucoxanthin content from S. polycystum. The results showed that both drying methods and solvents extraction had a statistically significant effect (p < 0.05) on fucoxanthin content in S. polycystum. Among three solvents extraction with two drying methods investigated, acetone extract from air-dried sample gave the highest fucoxanthin content (0.282 ± 0.08 mg/g DW) followed by ethanolic extract from air-dried sample (0.198 ± 0.13 mg/g DW). Sun-drying sample extracted with methanol yielded the lowest amount of fucoxanthin (0.028 ± 0.02 mg/g DW). Concisely, the best drying method to extract fucoxanthin from S. polycystum is air-drying method with acetone as the extraction solvent. [ABSTRACT FROM AUTHOR]

This study was conducted to evaluate the performance of an alcohol-based hand sanitizer spray as an affordable antimicrobial agent for controlling the spread of COVID-19. In this research, hand sanitizer spray was made from 70% alcohol as active ingredient; glycerol 11.65%; IPM 0.77%; essential oil 0.19%; and distilled water 17.39%. To determine the quality of hand sanitizer spray, organoleptic, homogeneity, pH, density, viscosity, dispersibility, adhesion, dry time, and anti-bacterial activity tests were carried out. The results of the organoleptic analysis showed that the preparation was liquid, clear in color with a distinctive aroma of coffee, and a pH of 6.5 - 7.0. Homogeneity of the preparations showed the stability of the constituent components of the emulsion with a density of 0.8-0.83 g/cm3, a viscosity of 2.5-4.0 cP, with a spreadability of 13-17 cm and adhesion of more than 1 second. Hand sanitizer spray products also show antibacterial activity against Eschericia coli, Staphylococcus aureus and Salmonella thypimurium. [ABSTRACT FROM AUTHOR]

This study aims to determine the effectiveness of graphite oxide (GO) material modified acetic acid as an antibacterial. Graphite oxide test material is modified by acetic acid with concentrations of 1%, 3%, and 5%. The results of the antimicrobial activity test obtained optimum concentrations for GO/Acetate material types with a concentration of 3% in Escherichia coli bacteria. The characteristics of GO/Acetate with Scanning Electronic Microscopy (SEM) showed there was a difference in the morphological surface of GO material modified acetic acid at a concentration of 5% with a tighter surface. The Fourier transform Infra Red (FTIR) results indicated absorption at wavenumbers of 3420, 3422, and 3439 cm−1 which sharp and very typical vibration of O-H group concluded that graphite oxide has water content in it. Wavenumbers of 1428 and 1385 cm−1, showed an acetyl group, CH3. Wavenumbers of 1627 and 1624 cm−1 displayed an aromatic C=C functional group. While wavenumbers of 1054, 1113, and 1029 cm−1 illustrated the C-O group. The antimicrobial activity test showed that the presence of acetate functional group on the surface of GO can improve the performance material as antibacterial agent. [ABSTRACT FROM AUTHOR]

This study studied the comparison of electrical potential, as well as the decrease in Chemical Oxygen Demand (COD) and Biological Oxygen Demand (BOD) Microbial Fuel Cell (MFC) using Ambon banana peel waste (MFC-KP) and tempeh waste (MFC-LT) as substrates. The MFC system used is dual chamber MFC with KMnO4 as catholyte and bentonite earthenware as membrane. Measurement of current and voltage every 2 hours during 48 hours. COD and BOD measurements were carried out before and after the waste was used in the MFC system. The measurement results show that the potential electricity of MFC-KP is higher than that of MFC-LT based on the parameters of current, voltage, and power density. MFC-KP has the highest current of 3.50 mA with an average of 1.75 mA, the highest voltage of 0.98 V with an average of 0.54 V, the highest power density of 111 mW/cm2 with an average of 43.05 mW /cm2. The T-test results for the measurement parameters of current, voltage, and power density resulted in significant differences. The significant difference in this parameter means that there is an effect on the use of ambon banana peel waste and tempeh waste as substrates of MFC [ABSTRACT FROM AUTHOR]

Phytophthora capsici L. is a fungus that causes stem rot in pepper plants. The provision of synthetic pesticides to control plants leaves residues that are harmful to the environment and human health. The plant-based fungicides are environmentally friendly and can be used as an alternative. The purpose of this study was to extract red galangal rhizome (Alpinia purpurata K.Schum) and determine its inhibitory activity against Phytophthora capsici L. In addition, identification of the active compounds contained in red galangal extract was carried out. The extraction method used is maceration and fractionation using vacuum liquid chromatography obtaining n-hexane fraction, ethyl acetate fraction , and ethanol fraction. The extract and fractions were determined their inhibitory activity against Phytopthora capsici L. The results showed that ethanol extract, ethyl acetate fraction, and ethanol fraction of red galangal were proven to inhibit the growth of the fungus Phytophthora capsici L. at any concentration. The best inhibitory activity of the fungus Phytophthora capsici L. was achieved by the ethyl acetate fraction at a concentration of 1.5% with an inhibition percentage value of 92.41% and classified as a very high activity level. Compounds that have the potential as antifungals in red galangal rhizome are flavonoids, saponins, phenolics, and terpenoids. [ABSTRACT FROM AUTHOR]

There have been review about modifications of metal oxides synthesis, characterization, and applications over the last 10 years approximately 35000 journals from Sciencedirect.com as data sources for metal oxide synthesis as photocatalysts. From a search engine of 35,000 journals discussing this matter, the filtering process in specific areas involved green and chemical environmental methods with the results of about 145 journals. Then a specific assessment was carried out that referred to natural molecular and non-toxic processes and improved the photocatalytic properties of the oxide to produce 19 comprehensively reviewed journals. The aim of this metal is to determine the potential of plant extracts or natural sources as support system agents in the synthesis of oxides from previously published journals by researchers. The properties of (solid) nanomaterials for photocatalyst applications from the last 10 years trend to produce catalysts with relatively good physical, electronic or chemical characteristics compared to previous strategies in semiconductor production. This study is not only a wider field of view in the development of the discovery of metal oxide nanoparticle catalysts but also useful for increasing the efficiency of photocatalysts for various applications in organic waste treatment. Modifications on the surface can be carried out using nature-based methods with the aim of improving various surface characteristics involving surface energy, and reactivity as well as charge kinetics, active sites, biocompatibility, and hydrophilicity to control physicochemical developments in photocatalysis. Keyword: metal oxide, synthesis, photocatalysts, green method [ABSTRACT FROM AUTHOR]

Analysis of the properties and characteristics of the internal pore structure of titanium oxide impregnated onto the surface of mesoporous silica from the gelatin template systematically has an important meaning for efficient application performance. In this research, mesoporous silica was synthesized using gelatin as a template then followed by impregnation of titanium oxide to produce TiO2/SG material which was calcined at 550 °C for 4 hours. The pore structure of TiO2/SG was analyzed by nitrogen adsorption with a low temperature of 300 °C degassing then analyzed on the adsorption isotherm using the BET method and pore size distribution using the BJH and t-plot methods. The isotherm of the TiO2/SG sample obtained by BET (Brunner, Emmett and Teller) method is categorized as type IV with the H2 loop hysteresis type which indicates that the TiO2/SG sample is a mesoporous material with tubular pores with surface area 550 m2/g. The distribution of the sharp pore size in the TiO2/SG sample measured at 38Å by BJH (Barrett–Joyner–Halenda) method from the data on the desorption branch which is intruded volume reaches closely to 73%. From t-plot result, the microporous areas of TiO2/SG were 197 m2/g from total surface area up to 550 m2/g du to the effect of the impregnation process which causes micropores in silica to be converted into micropores with a smaller size. [ABSTRACT FROM AUTHOR]

The adsorption kinetics of methylene blue with 1% TiO2/SBA-15 has been investigated. This research begins with the synthesis of TiO2/SBA-15 using TEOT (Tetra Ethyl Orto Titanate) as a source of TiO2 and SBA-15 as a support material using the wet impregnation method. The structure and physicochemical properties of TiO2/SBA-15 were observed by XRD (X-Ray Diffraction) and FTIR (Fourier Transform Infrared Spectrophotometer). The study of the adsorption kinetics of the experimental data on the adsorption of methylene blue to TiO2/SBA-15 will use several approaches, namely the Lagergren pseudo-first-order irreversible reaction model, Ho McKay pseudo-second-order reaction model, and the pseudo-Pandey first-order reversible reaction model. The results showed that the adsorption kinetics of methylene blue approached Ho Mckay's pseudo-second-order model where the adsorption rate was linearly related to the square of the number of adsorption sites with a material adsorption capacity of 106.7 mg / g which represented the material's ability to adsorb methylene blue molecules [ABSTRACT FROM AUTHOR]

The purpose of this work is to evaluate and asses the use of salacca skin waste as adsorbent for dye removal. The work was evaluating the physicochemical character of salacca skin waste (SS) and its biochar (SBC) form for the adsorption of methylene blue. The characterizations were conducted using SEM-EDX, gas sorption analyzer, Boehm titration, and FTIR spectroscopy. As for the adsorption experiments, a batch adsorption system was utilized. The adsorption isotherm kinetics data revealed the fitness of pseudo-second-order as indication of the dependency of the adsorption to the adsorbent capacity. The adsorption by both adsorbent is better adjusted to the Freundlcih model with the adsorption was about 92 mg/g. There is no significant difference between SS and SBC for their capacity, kinetics, and the effect of pH and adsorben dose, suggesting that SS gives more effectiveness for the simple preparation. [ABSTRACT FROM AUTHOR]

There have been reviews on the synthesis, characterization, modification, and application of TiO2 over the past 10 years in about 30,000 journals from the Sciencedirect.com website as a data source investigating capping agents and sensitizers from natural materials. The process of searching for data sources was continued with a filtering process according to several key words, namely "capping agent, sensitizer, natural, green, plant, extract" then obtained 25 selected articles that specifically reviewed the potential of plant extracts as capping agents and sensitizers in the synthesis of titanium oxide. The results of the review concluded that the shape and size of titanium oxide using a capping agent in the form of plant extracts such as starch, temulawak, soybean, aloe vera, curry tea, hibiscus rosa sinensis is spherical in shape with a size range of 7-160 nm and an average particle size of up to 30 -50 nm. Natural pigments and dyes such as anthocyanins and chlorophyll have been used as sensitizers in the last ten years. This review shows that the use of biomass as a source of capping agent and sensitizer increases efficiency because of the band gap and surface area. The plant extracts will provide several levels of efficiency in producing titanium oxide with various morphological variations and applications with band gap control. [ABSTRACT FROM AUTHOR]

To Aftermath of Tsunami tragedy at Japan on 2011, the catastrophic failure of the Fukushima I Nuclear Power Plant reactor resulted, release amount of radioactive caesium into the environment. In this study, non-polluted soil sample from Kotagede, Yogyakarta, Indonesia which has similar characteristic with Fukushima soil was prepared by artificially contaminated caesium (100 mg CsCl/kg soil) in five cycles of saturation process using de-ionized water and air-dried before being aged for five months and subjected to EKR treatment. The results obtained from those studies were used to predict the advantages of this technology in Fukushima soil. Physical and chemical of soil samples were characterized by X-Ray Diffraction for mineral contents and soil component analysis was measured for Organic Matter, Total Nitrogen, CEC and soil texture. EKR was conducted by using graphite electrode in constant voltage of 1 Vcm−1 for 7 days operation without control of electrolyte pH. Current flow in the soil was recorded for every 10 mins. by using data logger. The effect of electrolyte (e.g. 1 M acetic acid and carbonate salt) was also evaluated. All caesium concentrations were measured by flame-atomic adsorption spectrophotometer at wavelength of 852.1 nm. The results of these experiments showed that the type of electrolyte used in the experiments affected the rate of caesium removal. The removal caesium by acetic acid was higher than removal caesium by carbonate salt. Total removal of caesium concentration by acetic acid as electrolyte in soil A, B, C, D were 24.3%, 20.5%, 25.6%, 19.4%, respectively and the percentage of removal caesium concentration by carbonate salts as electrolit in soil A and B, C, D were 11.8%, 11.7%, 11.8%, 4.3%, respectively. [ABSTRACT FROM AUTHOR]

Ruku-ruku (Ocimum sanctum, L.) and selasih ungu (Ocimum canum, Sims.) were local types of basils (Ocimum basilicum, L.) found in Indonesia. They exhibited a good fruit fly attractant activitiy as they contained a specific chemical known as methyl eugenol. Fruit fly often pointed out to responsible for damage of some agricultural products such as melon and chili in local districts. This paper was to show the effects of addition of virgin coconut oil (VCO) on oil-based trapper in reducing the population of fruit fly and as part of pest control to the local farmer that synthetic pesticide utilization was remarkably high. Essential oil of each species of purple basils obtained from aerial part of plants and conducted by steam distillation. Each essential oil of purple basils was formulated with VCO in several ratio depending on the methyl eugenol contain that obtained from GCMS analysis with total volume 1.0 – 1.5 mL of liquid bait. Fruit fly trapper (FFT) was made from yellow color plastic bottles and placed at 1.0 m of height on the specific level of farm. In this research, FFT bait consisted of VCO formulated essential oil of ruku-ruku (Ocimum sanctum, L.) (REO-VCO) was placed on the melon farm and selasih ungu (Ocimum canum, Sims.) (SEO-VCO) on chili farm. GC-MS analysis indicated the methyl eugenol content of ruku-ruku essential oil (REO) was 61.08 % (22722553 in.peak area respectively) while methyl eugenol content of selasih ungu essential oil (SEO) was 53.44 % (36377188 in.peak area respectively). From the field study analysis and observation showed that the addition of VCO increasing the attractancy activity of the essential oils regarding of the essential oil itself. REO-VCO (618 trapped fruit flies; 200 male) showed higher activity compared to SEO-VCO (114 trapped fruit flies; 39 male). All formulated essential oils were effectively attract for female fruit fly dominantly. [ABSTRACT FROM AUTHOR]

The diethanolamide surfactant from waste cooking oil using zeolite supported potassium carbonate (K2CO3/zeolite) catalyst was successfully synthesized. The zeolite was activated by acid treatment followed by impregnation of K2CO3 at various K2CO3−to-zeolite ratios of 2:1, 4:1, and 6:1. K2CO3/zeolite catalysts were analyzed by Fourier transform infrared spectrophotometer (FTIR) and X-ray diffractometer (XRD). The transesterification reaction was performed to convert waste cooking oil into methyl ester using potassium hydroxide (KOH) catalyst. The transesterification product was confirmed by FTIR spectrophotometer and gas chromatography-mass spectrometer (GC-MS). The obtained methyl ester and diethanolamine solution were refluxed over K2CO3/zeolite catalyst to produce diethanolamide surfactant. The formation of diethanolamide was monitored using FTIR spectrophotometer. The surface-active properties of diethanolamide surfactant were assessed in terms of foam stability, emulsion index, and surface tension. The reaction of methyl ester and dietanolamine using K2CO3/zeolite with K2CO3−to-zeolite ratio of 2:1, 4:1, and 6:1 successfully produced diethanolamide surfactant with total conversion of 86, 92, and 89%, respectively. K2CO3/zeolite (6:1) catalyst produced the highest foam volume and emulsion index of 33.91 cm3 and 68.60%, respectively. The diethanolamide surfactant produced from amidiation reaction over K2CO3/zeolite (6:1) catalyst showed stable foam and emulsion with the reduction of surface tension of 8.46 dyne/cm. [ABSTRACT FROM AUTHOR]

Kaffir lime oil has been isolated from fruit peel and leaf with different preparations. The fruits and leaf were obtained from Sedayu sub-district, Bantul Regency. The raw materials are prepared into different form i.e. grinded peel (A), pieces peel (B), grinded leaf (C) and intact leaf (D). Each raw material is distilled using water distillation equipped with an aluminum barrier between the materials and water for 3 hours. The highest yield is obtained from grinded peel (3.06%). Other physicochemical properties showed almost uniform results, with a refractive index of 1.447 - 1.469, specific gravity of 0.821 - 0.859 and showed a clear colorless to clear slightly yellowish. Optical rotation is the only parameter whose results vary widely. The results of the GCMS analysis showed that there were no significant differences in the compounds obtained from the different treatments of the raw materials. The majority of compounds identified are sabinene, β-pinene, limonene, linalool, citronellal, 4-terpineol and citronellyl acetate. However, the chemical compounds found in the grinded peel are more diverse than others. The majority of compounds obtained from kaffir lime peel are sabinene, β- pinene and limonene, the concentration of these compounds is higher than in the leaves. Whilst, the dominant chemical compound in the leaves is citronellal. It has been found that the different preparations of raw materials resulted in different yields, mainly in the peel, whereas in the leaf, there was no significant difference. Material preparation does not really affect the difference in the physico-chemical properties of the oil. [ABSTRACT FROM AUTHOR]

Cancer was deadly disease in the world that the case in the world including Indonesia increase every years. Rutin (Quarsetin-3-O-Rutinoside) was anticancer compound that was found in many Indonesian native plants. The researchers was trying to find effective drug candidates for cancer diagnostic using radiopharmaceutical Tc99m-rutin and therapy both with diagnostic using radiopharmaceutical I131-rutin. AKR1C3 protein (17β-hydroxysteroid dehydrogenase tipe 5) was the part of prostate cancer cells, breast cancer and endometrial cancer that was influenced by hormones. I131-rutin was been docking with AKR1C3 protein using the autodock vina program. It's was successfully docked with best binding affinity energy -10.1 kcal/mol. It's was found 4 hydrogen bonds and 2 phi bonds from this molecular docking. And for Tc99m-rutin was successfully too with best binding affinity energy -9.4 kcal/mol. It's was found 1 hydrogen bonds and 2 phi bonds from this molecular docking. Furthermore, this I131-rutin and Tc99m-rutin must be continued to the molecular dynamic step before ready to be synthesized and used in in-vivo tests for radiopharmaceutical candidate. [ABSTRACT FROM AUTHOR]

A preliminary study of electrochemically citronellal conversion has been studied for the first time in a one-pot (single chamber) electrolytic cell using a platinum working electrode. This study aims to develop a facile citronellal conversion method to produce more valuable derivative products. Linear sweep voltammetry was performed in the various ethanol mixture electrolytes (0.1 M HCl, KCl, and NaOH) from 0.5 to -1.5 V vs Ag/AgCl at a scan rate of 100 mV/s to evaluate the reduction peaks of citronellal. A peak at -0.5 V vs Ag/AgCl was observed using the ethanol+0.1 M KCl mixture electrolyte predicted as a reduction peak of citronellal. Furthermore, a reduction product was evaluated using chronoamperometry technique at a constant potential of -0.5 V vs Ag/AgCl for 2 hours produced menthol (46.92%), isopulegol (32.12%), and p-menthane-1,3-diol (20.96%) as the products. This result revealed a potency of electrochemically citronellal conversion conducted in a simple one-pot electrolytic cell. [ABSTRACT FROM AUTHOR]

Carbohydrates are the main source of energy that can be obtained from consuming food. Determination of carbohydrates in the food industry is important. Flour of snake fruit seed is a source of carbohydrates. Determination of carbohydrates can be done using the colorimetric method. However, to date, no research has been conducted into the validation of an analytical method to determine carbohydrate in flour of snake fruit seed. In this study, validation of the method for determining total carbohydrate in flour of snake fruit. Parameter of method validation measured include linearity, limit of detection, limit of quantification, precision, and accuracy. The regression curves gave the value of R2 0.9977. For limit of detection and limit of quantification values in the flour of snake fruit seed were 2.6850 and 8.9501 mg/L, respectively. The accuracy result were found in the range of 87.50-116.67 % with good precision value (% RSD <2%). Thus the method was acceptable to be used for determination total carbohydrate in flour of snake fruit seed. [ABSTRACT FROM AUTHOR]

The leather tanning industry is known as an industry that is not environmentally friendly because it produces a lot of waste in the process. The resulting liquid waste contains heavy metal chromium (Cr), high chemical oxygen demand (COD), and several other nutrient compounds that can be decomposed by microorganism. By utilizing Microbial Fuel Cell (MFC) or microbe-based electrochemical cells, this is an example of alternative technology that can be developed as replacement energy because this fuel cell converts chemical energy into electrical energy using microorganisms. In the research conducted, MFC Dual Chamber was used with aluminum as the electrode and there were two substrates, namely glucose as a nutrient and rice field mud as a biocatalyst from microbes found in tannery wastewater. After observing the value of electric power which shows the existence of an electric potential, in variation 1, namely liquid waste from leather tanning with glucose substrate and rice field mud, the power is 167.13 Watts. As for variation 2, which is liquid waste from tanning leather with glucose substrate, the power obtained is 48.11 Watt, and for the last variation, namely the three liquid wastes from tanning leather with rice field mud substrate, the resulting power value is 13.54 µWatt. From the results of research that has been carried out, it is proven that the treatment of leather tanning liquid waste using the MFC Dual Chamber method can generate electrical potential. And with the addition of substrate in the form of rice field mud and glucose as a source of microbes and nutrients for liquid waste can produce a higher electrical potential. [ABSTRACT FROM AUTHOR]

Pumice is a pyroclastic rock that is abundantly available in Indonesia. Alkaline-activated pumice powder can be utilized as adsorbent for cationic contaminants in water environment owing to its mineralogical and chemical characteristics. These characteristics of pumice are site-specific. This study aims to determine the differences in mineral composition and chemical characteristics between pumices sampled from Kalianda site, Lampung, Sumatera, and Kediri site, East Java, Indonesia and their potential usage as adsorbents for cationic heavy metal lead (Pb) contaminants in water environments. Sampling site of the Kediri pumice was far away to the eastern from that of the Kalianda pumice. Isothermal adsorption test was carried out using adsorbents prepared from NaOH-activated pumice powder of 74 µm grain size in batch experiments. The results showed that amorphous minerals in the form of pumice dominated Kalianda pumice, while Kediri pumice was dominated by volcanic glass and plagioclase feldspars. Kalianda pumice has a finer grain size distribution than that of the Kediri pumice. The Pb adsorption maxima of Kalianda and Kediri pumice adsorbent were 37.31 and 28.49 mg g−1, respectively. [ABSTRACT FROM AUTHOR]

Currently the sugar factory industry in Indonesia is growing rapidly and the demand for sugar is getting higher. From the production process, the sugar factory industry produces liquid waste that contains high organic compounds so that it has an impact on the environment. To reduce these negative impacts, this review highlights the application of bagasse as an ingredient to treat sugar mill effluent. In handling sugar factory effluent, the processing includes activation, modification and application of modification methods such as chemistry and physics. From these modifications, physical modification considers the contact time, carbonization temperature, and mass of activated carbon. Chemical modification takes into account the pH value. In addition, the treatment of bagasse wastewater using bagasse as an adsorbent aims to reduce unused waste and overcome environmental impacts. Sugar factory effluent contains high quality organic compounds that have the potential to have a negative impact on the environment. Therefore, we need to reduce the negative effects on processing in sugar factories. The processing includes pre-treatment and treatment to reduce liquid waste. In the processing there are physical and chemical modifications. Physical modification based on contact time, carbon temperature, and mass of activated carbon. Chemical modification based on pH value and dosage. In addition, the conversion of bagasse to activated carbon is used to reduce the waste generated by sugar factories and to reduce the impact on the environment. [ABSTRACT FROM AUTHOR]

Hand sanitizer is the main ingredient during the Covid-19 pandemic to prevent transmission to humans. There are many hand sanitizers circulating with various brands without any description of their chemical composition. The main ingredient of hand sanitizer is ethanol. The ability of hand sanitizers depends on the ethanol content. Ethanol has the property of killing the Covid-19 virus. The purpose of this study was to determine the ethanol content in 5 samples of hand sanitizer preparations using gas chromatography with a valid test method. The instrument used is gas chromatography. The ethanol content of the five hand sanitizer preparations was 74.80; 76.78; 51.74; 79.53; and 56.09%. Hand sanitizers circulating with sample codes A, B, and D meet the World Health Organization standards, which are 60-95%. The results of the test method validation indicate that the test method used for ethanol analysis on hand sanitizer samples by gas chromatography is a valid and feasible method to use. [ABSTRACT FROM AUTHOR]

Industrial waste containing dyes is difficult to process. Effective and efficient waste treatment technology is needed to treat dye waste. This study conveys the results of processing dye waste using a combined method of oxidation with hydrogen peroxide and coagulation using alum. The research parameter analysed was Chemical Oxygen Demand (COD) using a UV-Visible spectrophotometer. This study was influenced by several factors, namely the concentration of H2O2, stirring time, volume of H2O2 and variations in the addition of alum mass. The results showed that the reduction in COD with hydrogen peroxide concentration of 10%, stirring time for 40 minutes, volume of hydrogen peroxide as much as 1 mL, and alum dose of 2.5 g with an efficiency of decreasing COD concentration of 90.14%. The conclusion is that the combination of the two methods can be used as a pre-treatment method and further treatment is needed to produce COD levels that are in accordance with the waste quality standards. [ABSTRACT FROM AUTHOR]

Coagulation and flocculation are commonly used in water and wastewater treatment. Despite its high effectiveness, utilization of inorganic metal salts as coagulant and flocculant might cause negative impact to the environment and human health. As an alternative to tackle this problem, the use of natural coagulants and coagulant aids is suggested. In this study we reported utilization of gelatinized durian starch as coagulant aid to treat synthetic Congo red wastewater. The starch was extracted using a wet milling process and obtained as white starch powder. Alum was used as the coagulant in this study, with the best coagulation pH was obtained at pH 7. The gelatinized durian starch was then added as coagulant aid at various doses. However, addition of coagulant aid did not give significant changes to the Congo red removal, and increased the sludge volume formation. Best coagulation condition was obtained at pH 7 and alum dose of 30 mg/L that resulted in 91.4% removal and 13.6 mL/L sludge volume, without the presence of coagulant aid. Further study is needed to improve coagulation ability of durian starch. [ABSTRACT FROM AUTHOR]

This study aims to analyze the needs of students and teachers for chemistry learning resources. This research is a preliminary study that is part of the development of chemistry learning resources. The technique of data collection was done through a questionnaire. The research sample is students and teachers from five schools in Yogyakarta. Data analysis was carried out in a quantitative descriptive. The results showed that 68% of students were happy and interested in learning chemistry. However, 78% of students admitted to having difficulties in learning chemistry. Furthermore, they stated that 66% of the learning resources they used in learning chemistry were not enough to help in understanding the material. 59% of the learning resources they use have not been able to make them interested and happy to learn chemistry. Based on this, 81% of students stated that it was necessary to developed learning resources in the form of chemistry magazines. 83% of students agreed that the chemistry magazine could be an interesting and fun learning resource. [ABSTRACT FROM AUTHOR]

The Covid-19 pandemic has shifted the format of the implementation of the teaching and learning process and has greatly impacted the fulfillment of competencies inherent in courses. This impact is very influential on practice courses, especially in the fulfillment of laboratory chemistry skills. Therefore, a simulator instrument was developed as a virtual laboratory in the implementation of online practice courses. The simulators developed are UV-Vis Spectrophotometer and Atomic Absorption Spectrophotometry (AAS). In the blended practice course format where 85% of the meetings are held online and 15% of the meetings are held offline, the simulator is used in the online practice course. The purpose of using the simulator is to improve students' skills in operating the instrument. The results of the survey of student perceptions of the use of the simulator stated that the majority of respondents strongly agreed or agreed with the ease of downloading the simulator, the ease of operating the simulator, the use of the simulator was very helpful in operating the instrument in the laboratory and the time spent completing the simulator was comparable to a traditional laboratory. The survey results also state that in the teaching and learning process, the majority of respondents also strongly agree or agree that experiments strengthen theory, experiments help in understanding concepts, the material provided helps in competency testing and online practice course help in understanding concepts such as traditional practice course. [ABSTRACT FROM AUTHOR]

A pharmacist is a professional health worker who focuses on all aspects of medicine, starting from the manufacture to the effectiveness of the drug used by patients. Graduates of the pharmacist profession must undergo a bachelor of pharmacy study program and continue the pharmacist profession study program. The professional study program is achieved in one year consisting of 2 semesters with various activities, both lectures with the university teaching team to field practice. The majority of undergraduate students who graduate from pharmacy will continue their study of the pharmacist profession. Usually they have high enthusiasm and motivation to complete the program. Therefore, the researcher wanted to know the motivation and gaze of the students at the beginning of the pharmacist program semester using the motivated strategies for learning questionnaire (MSLQ). Thus, students are expected to be able to identify their own motivation and develop strategies to optimize their learning performance while in the pharmacist profession program. This descriptive research design uses a cross-sectional approach. The research sample is a pharmacist profession student at the beginning of the first semester. Primary data was collected from filling out the motivated strategy for questionnaire learning by students, and data was taken from the final grade of learning in the first course. Respondents involved as many as 97 students with male sex 21.43% and the rest female. The results of data analysis showed that the level of motivation and strategy had the same results in the high category of 43% and 57% of the moderate category. The results of the analysis showed that of the 81 MLSQ there were 39.51% positive and negative correlations, respectively, while the rest were uncorrelated. This shows that students who have a high level of motivation and strategy show grades that will be well received, and vice versa. Therefore, from this research it is locked that motivation and strategies affect student learning outcomes. [ABSTRACT FROM AUTHOR]

The aim of this study is to investigate the perception of students who attending online learning of physical pharmacy laboratory work. Online questionnaires were used to gather student perspectives on online learning that was conducted using several online learning platforms i.e Zoom Cloud Meeting, Google Classroom, Google Docs, Google Sheets, Panopto, and Quizizz. Questionnaires contains the closed questions about student's demographic, devices used during online learning, source of internet connection, use of online learning tools or platforms, the internet connectivity issues, their perceptions about the learning tools and the online learning process. One hundred and sixty one students, whom were divided into six classes, were surveyed. The results indicated that various devices preferred by students for attending online course were laptop (77%), tablet/ smartphone (3.1%), personal computer (1.9%) and combination of these devices (18%). WiFi was the main source of internet for students (77.5%), while 33.5% of students stated that they use mobile data package to participate in the online learning. As much as 31.7% of the students reported that they often experience internet connection issues during Zoom meeting, while only 0.6 % of students stated that they never experienced it. About a quarter of the students said that they never experienced technical problems when accessing Google Classroom, while 70.8% of students stated that they rarely experienced it. Most of the students stated that online learning platforms helped them during the learning process so that they got a better understanding about the course. More than 50% of students were enthusiastic about participating in online learning and find it enjoyable. Overall, students have positive attitude towards online learning of laboratory work during Covid-19 outbreak, despite some technical hindrance and no experience of using laboratory instruments. [ABSTRACT FROM AUTHOR]

As pre-service chemistry teachers, particularly in this digital era, it is crucial to understand and develop skills in the TPACK aspects so that they have a good understanding and skills in integrating technology, pedagogy, and content according to their context and function. The understanding of TPACK must be given since they were before becoming teachers. Although the development of TPACK for pre-service teachers is not easy to achieve, it must be done so that the quality of teachers can be even better. Each teacher can have a different TPACK with other teachers. In addition, the variables such as the subject or lesson, gender, and used technologies can also affect the confidence in pre-service teachers' TPACK. Therefore, this study aims to determine pre-service chemistry teachers' confidence in their TPACK after completing Microteaching lectures. The microteaching course is specifically designed to prepare students to be ready to teach in schools. Furthermore, this study also measures the impact of the microteaching course on pre-service chemistry teachers' TPACK. Data were collected using questionnaires, interviews, and reflective journals. This study indicates that, after completing fully online microteaching lectures, pre-service chemistry teachers are very confident about their TPACK. Besides, students also really feel the impact of microteaching lectures on all aspects of their TPACK. [ABSTRACT FROM AUTHOR]

The implementation of PBL with rich context insight has been conducted in SMA N 2 Sleman, Yogyakarta. This experiment research aims to know if there is a significant difference in the metacognitive ability of students that learn in PBL and the class discussion model. The population is students of grade XI social sciences in SMA N 2 Sleman which is divided into 2 classes. The metacognitive ability was assessed for self-planning, self-monitoring, and self-evaluation aspects. Learning achievement was measured for knowledge and attitude aspects. Data was taken by questionnaire and analyzed by Non-parametric Mann-Whitney test for the metacognitive ability. Learning achievement was taken by multiple-choice questions and questionnaires for knowledge and attitude aspects, respectively. The hypothesis was tested with Mann-Whitney for knowledge aspect, while the attitude used independent Sample T-Test. The result showed that there was significant difference in the metacognitive ability and attitude of students that learn in PBL and the class discussion model with sig. value of 0.016 and 0.037, respectively. Furthermore, it was found that there is no difference in the knowledge aspect in learning achievement. Determination of category showed that the metacognitive ability of students with PBL with rich context insight was good, while the attitude was very good. [ABSTRACT FROM AUTHOR]

The development of teacher competences is an important issue in various countries, including Indonesia. Improving teacher competences is described in various programs of the Ministry of National Education. In 2017 the Indonesian government passed a regulation on Teacher Education Standards, the regulation regulates in detail the learning outcomes program for prospective teachers, this is intended to ensure that prospective teachers have competences. One of the compulsory subjects that must be taken by prospective teachers is microteaching. Learning about how to teach requires feedback, coaching to monitor and improve teaching performance. During the Covid-19 pandemic, micro teaching is carried out online. This of course requires a strategy so that prospective teachers still have teaching skills. In general, during micro teaching, prospective teachers will take turns doing teaching practices and then get feedback from their supervisor lecturer. Different from the general conditions, this research is focused on the implementation of peer feedback. The purpose of this study is to determine the impact of peer feedback on teaching skills. The research subjects are all students who take micro teaching courses for the 2020/2021 academic year. The research data shows that students' teaching skills have increased, 70% of students have increased with high criteria, 26% with medium criteria, and 4% with low criteria. [ABSTRACT FROM AUTHOR]

The achievement of clinical chemistry course scores that have not met the target of the study program for the last 4 years has motivated the existence of learning innovations in this course. In the previous year, the learning method was blended learning, with teacher center learning still being dominated (60%). Therefore, learning in the year of 2020/2021 was carried out using a combination method of online flipped classroom and case base learning. The online flipped classroom method is a modification of the flipped classroom that has been widely used before, by providing material asynchronously through learning media followed by synchronous discussion of the material using online media. Student understanding is also strengthened by providing cases that are solved in groups using the case-based learning method which is carried out at the end of each explanation of the study material. The implementation of online flipped classroom and case base learning which is carried out alternately has received a positive response from students. The learning evaluation shows the final grade of the course which increases dramatically and exceeds the target set by the study program. [ABSTRACT FROM AUTHOR]

The aims of this study are: 1) To know the criteria for parental support of students in chemistry lessons; 2) Knowing the criteria for student interest in chemistry lessons; 3) Knowing the relationship between parental support and student interest in learning chemistry during the Covid-19 pandemic. The population in this study were students from three Vocational High Schools (SMK) in Pekalongan. The sample in this study consisted of Grade 10 from three schools, namely SMKN 1 Sragi, SMKN 1 Kedungwuni and SMK Gondang. Grade 10 from SMKN 1 Kedungwuni has 100 students, grade 10 from SMKN 1 Sragi has 227 students, and grade 10 from SMK Gondang has 35 students. Data collection in this study used a non-test in the form of a questionnaire. The data analysis technique in this study uses non-parametric correlation analysis, namely the Spearman test. This Spearman test begins with the analysis prerequisite test, namely the normality test and linearity test. Based on the results of the study, it showed that: 1) Parental support for students during the covid-19 pandemic at two Vocational High Schools in Pekalongan was in the good category, and one school was in the very good category; 2) The interest of students in studying chemistry at three vocational high schools in Pekalongan is in the good category; 3) There is a significant relationship between parental support and student interest in learning at SMKN 1 Kedungwuni where the significance value is 0.000 and the correlation coefficient is 0.684. There is also a significant relationship at SMKN 1 Sragi which has a significance value of 0.016 and a correlation coefficient value of 0.16. There is also a significant relationship between parental support and interest in learning of SMK Gondang students who obtained a significance value of 0.001 and a correlation coefficient value of 0.228. [ABSTRACT FROM AUTHOR]

This study aims to determine implementation in learning using the Pair Check Model viewed from the cognitive domain in students learning achievement on the buffer solution. The population of this study was all students of class XI in the SMA N 1 Kalasan, Yogyakarta. The research sample was taken as much as one class consisting of class XI IPA 1 as many 32 students. The sampling technique was carried out by purposive sampling. The instrument used in this study is test instruments in the form of an objective question instrument (multiple choice) for the cognitive domain. Based on results it can be concluded Based on these results, it can be concluded that the application of the pair check learning model provides an average value of a good cognitive domain in the buffer solution material of 86.54. Pair check learning can be used as one of the variations of learning chosen by the teacher to keep the student learning process focused, especially on buffer solution material. Students can familiarize themselves through the Pair Check learning model, to train critical thinking and solve problems through collaborating in pairs by uniting the power of thinking together. [ABSTRACT FROM AUTHOR]

Modules are important teaching materials to be developed in the learning process. The discovery learning teaching module is one solution that can help students distinguishing between oxidation reactions, reduction reactions, oxidizing agents, and reducing agents. This study aims to develop a product in the form of a discovery learning-based teaching module to measure students' cognitive abilities on redox material. The method used in this research is R & D (Research and Development) with a 3D development model, namely Define, Design, and Development. The results obtained from the experts on the product are valid in terms of material with a percentage value of 89.17% and in terms of media with a percentage of 91.4%. The effectiveness of using the product developed was tested at Pangudi Luhur St. Louis IX Sedayu Senior High School Yogyakarta with the results of the pre-test and post-test of students calculated by the gain score formula and obtained an increase of 0.56 with moderate criteria. The results of the student response questionnaire are an average percentage of 80.13% with a good category while the teacher's response gets a very good category with a percentage of 94%. The use of discovery learning-based teaching modules on redox reaction materials is valid, effective, and practical to improve students' cognitive abilities. [ABSTRACT FROM AUTHOR]

The objective structured clinical examination (OSCE) has been implemented as an assessment of pharmacist education. It can measure the ability of pharmacist students both structurally and objectively. But since the pandemic of Covid-19, the implementation of OSCE must be switched into an online method. Therefore, this study was aimed to evaluate the implementation of the first online OSCE for students in the pre-registered pharmacist program of the Department of Pharmacy UII, especially in pharmacy management course. It focused on the drug management cycle including selection, procurement, distribution, and use. Using the same competencies as the offline method, the online OSCE was designed and applied to apothecary student batch 37. It covers information and data collection, defining and solving the problem, and professionalism. The student and the examiner were met online via Zoom platform and mediated by Google Classroom for submitting the worksheet. There were five stations (selection and procurement, drug reception, distribution, drug storage, documentation, and report) that must be completed for each student with a duration of 10 minutes per station. The examiner evaluated student's performance based on the rubric to assure objectivity. To evaluate the effectiveness of online OSCE, the student's mark of batch 37 was compared to batch 36 that used an offline method. Based on the result, the final score of batches 36 was higher than 37, 82.33 versus 70.72 respectively (p<0.05, CI: 7.21±16.01). Technical problems on the online method such as devices, internet connection, and data plan have been strongly impacted on student's performance during OSCE. Moreover, the IT skill of students also took effect on stations that require documentation or report using worksheets. In conclusion, many obstacles in the first online OSCE implementation reduced the final mark of students. A comprehensive effort on enhancing student's readiness for online learning and system adjustment on online OSCE is important for further implementation. [ABSTRACT FROM AUTHOR]

The presence of a chemistry practicum module is important for the implementation of practicum in the vocational school. The practicum module is needed so practicum can run smoothly, learning objectives can be achieved, and reduce the risk of work accidents. On the other hand, the use of chemicals in the school is still quite large and the utilization of organic waste as practicum material is still limited. There is a need for an environmental friendly and integrated chemistry practicum procedure. Therefore, it is necessary to have an environmentally friendly chemistry practicum innovation for the subject of Organic Material Analysis in vocational high school. This research aims to develop an environmental friendly chemistry practicum module that utilizes fruit waste as practicum material for the production of ethanol, acetic acid and ethyl acetate. The integrated chemistry procedure is introduced in this practicum which uses products from the first practicum (ethanol) as a reactant for the production of the second practicum (acetic acid) and the third practicum (ethyl acetate). This is a research and development with ADDIE development model. The validity of the environmental friendly chemistry practicum module was assessed by validators; the effectiveness of the module was evaluated based on the score of students' practicum reports; and the practicality of the module was evaluated from students' responses using questionnaire. The environmental friendly chemistry practicum module is very valid criteria with an average percentage of 94.672%; very effective criteria based on the score of students' reports with an average score of 87.515; and very practical with an average percentage of 90.555%. It can be concluded that the environmental friendly chemistry practicum module is valid, effective and practical. The environmental friendly chemistry practicum module can help the students for conducting experiments and promote students' attitude concern towards the environment. [ABSTRACT FROM AUTHOR]

Research development of Scientific Critical Thinking (SCT) model learning devices based on Sasirangan local wisdom to improve creative thinking skills of electrolyte and non-electrolyte solution topics aims to produce valid, practical, and effective learning devices. The development model used is a 4D model that has to define, design, develop and disseminate stages. However, the dissemination stage was not implemented. Limited trials of developed learning devices were conducted on Chemistry School 2 students. The data collection techniques were through validation sheets, implementation sheets, and tests. The data were analysed using descriptive analysis. The results showed that the developed learning device had met the following criteria: (1) the SCT model device was valid because the lesson plan, worksheet, teaching materials, and test instruction components were in the valid category; (2) SCT model devices are practical because the phases of the SCT model can be carried out properly, and (3) SCT model devices are effective because of N-Gain creative thinking skills of 0.66 with moderate criteria. The results showed that Scientific Critical Thinking (SCT) model learning devices based on Sasirangan local wisdom topic electrolyte and non-electrolyte solutions are feasible and used in chemical learning. [ABSTRACT FROM AUTHOR]

This study aims to develop a four-tier assessment that is used to detect student misconceptions about salt hydrolysis. This type of research is development research using a 4D model (define, design, develop, disseminate). The sample in this study were 3 expert validators to test the feasibility of the assessment and 10 students for small class trials. Based on the results of the study, it was shown that from the feasibility test of the assessment by 3 expert validators, an average of 4.2 was obtained with the category suitable for use. Assessment trials in small classes show that the highest misconception is in the indicator of analyzing salt compounds that are in accordance with the experimental results, namely 60% of students, calculating the pH of salt solutions from strong bases and weak acids by 50% of students, determine salt compounds based on the pH value of 50% of students, analyze mixtures that undergo partial hydrolysis and are acidic by 50% of students and 50% of students who have misconceptions on indicators analyze the reaction equation of hydrolysis of acidic salts. The developed four-tier assessment can be used to detect students' misconceptions about the salt hydrolysis material. [ABSTRACT FROM AUTHOR]

The purpose of this research is to analyze the teachers' need for acid-base chemistry learning module based on 7E learning cycle model to practice critical thinking skills and foster learning motivation of high school students during the COVID-19 pandemic. This research is a descriptive qualitative study. The participants are 14 chemistry teachers from 10 high schools in Tulungagung, Indonesia, who were selected using purposive sampling technique. Data were collected using an online questionnaire containing semi-closed questions and analyzed using descriptive statistical analysis techniques. Based on the results of questionnaire, most teachers changed their learning methods during the pandemic. As many as 72% of teachers teach using the assignment method. This condition causes all teachers to need other teaching materials besides textbooks that can make students master chemistry well, especially on acid-base topic, which is difficult for students to learn. The module is one of the learning materials whose presentation flow can be arranged using learning model, for example, a module based on 7E learning cycle model. The 7E learning cycle model is considered to be able to improve students' critical thinking skills and learning motivation because it encourages them to be active in learning activities. Therefore, all teachers responded that it is necessary to develop acid-base chemistry learning module based on 7E learning cycle model. [ABSTRACT FROM AUTHOR]