bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analyze of chemistry teacher profiles using Technological Pedagogical and Content Knowledge (TPACK) framework
Authors: Paristiowati M , Hadinugrahaningsih T , Fitriani E , Imansari A , Nurhadi M F 
Published: December 2019

Abstract
This study aims to analyze the profile of technological pedagogical and content knowledge (TPACK) chemistry teachers at one of the schools in Jakarta. The criteria for the teachers analyzed are professional teachers who have been certified and have more than 20 years of teaching experience. The method used in this study is a qualitative descriptive research method. The data sources were collected through the TPACK questionnaire, lesson plan analysis, observation of the learning process, and interviews. The results show that chemistry teachers can apply learning methods that vary each meeting according to the characteristics of acid-base material. The teacher also utilizes technology information & communication (ICT) based learning media to simplify and clarify material delivery. It can be concluded that teachers have pedagogical content knowledge (PCK) and technological content knowledge (TCK). The use of ICT media such as interactive power points, videos and mobile phones to support selected learning methods, shows that teachers are also competent in technological pedagogical knowledge (TPK). The results of the study concluded that the teacher had integrated all TPACK components into acid-based learning so that they belonged to the action category (Action Level/An) at the TPACK competency level. This result was obtained base on CK, PK, TPK competencies that met the standard conception (Cn) category, and TK, PCK, TCK competencies that met the standard perception (Pn) category. Cn are indicated by understanding theories about TPACK components and their implementation through learning. While the Pn only understands the theories of components from TPACK.
Ab initioMP2 and DFT studies of ethyl-p-methoxycinnamate and its derivatives as corrosion inhibitors of iron in acidic medium
Authors: Hadisaputra S , Purwoko A A , Hakim A , Savalas L R T , Rahmawati R , Hamdiani S , Nuryono N 
Published: December 2019

AbstractThe efficiency of ethyl-p-methoxycinnamate(EPE) and its derivatives as corrosion inhibitors of iron in acid environment has been studied to find the relationship between molecular structure and electronic parameters with their efficiency of corrosion inhibition. Theab initioMP2 perturbation theory and DFT method were applied to calculate molecular structure and electronic parameters of inhibitors. Computational and experimental corrosion inhibition efficiency show that the electronic properties of molecules, including the orbital molecular frontier energy (HOMO and LUMO energy), ionization potential, electron affinity, electronegativity, number of electron transfer from inhibitor to metal and interaction energy have a strong relationship with inhibition performance. Interaction mechanism obtained from natural bond orbital analysis was employed to study the interactions between inhibitors with iron metal in more detail. The presence of electron donor groups within the frameworks of inhibitors has a less significant effect compared to π-electron contribution on corrosion inhibition performance.
A culturally responsive teaching approach and ethnochemistry integration of Tegal culture for developing chemistry students’ critical thinking skills in acid-based learning
Authors: Rahmawati Y , Baeti H R , Ridwan A , Suhartono S , Rafiuddin R 
Published: December 2019

Abstract
The aim of this study was to develop students’ critical thinking skills through a Culturally Responsive Teaching (CRT) approach and ethnochemistry of Tegal culture. The teaching approach focused on exploring the culture and local wisdom in Tegal Culture, especially in Acid-Base such as the Nginang, Moci, and Jamasan traditions from chemistry perspectives integrated into CRT. The study employed a teaching model consisting of five phases; self-identification, cultural understanding, collaboration, critical reflections, and transformative construction. The study involved 35 year 11 students from a secondary school in Balapulang Tegal. A qualitative methodology approach was employed using observation, interviews, a critical thinking test, and reflective journals as data collection methods. The results show that the integration of ethnochemistry in a CRT approach engaged students in developing their critical thinking skills by developing a conclusion, making connections, conceptual understanding, and interpretation with the critical thinking skills test which shows 40% of students reached level 3 (Satisfactory). In addition to the students engaging in the cultural identity empowerment, meaningful chemistry learning experiences, and team work, the students were challenged in developing their critical thinking skills.
Analysis of water quality and hotel liquid waste in Ubud Region, Gianyar
Authors: Pratiwi A E , Sumadewi N L U 
Published: December 2019

Abstract
A research on the analysis of water quality and hotel liquid waste in Ubud sub-district, Gianyar-Bali has been conducted. The analysis of raw water quality was done to discover whether the raw water can be appropriately classified as clean water. The parameters used in analyzing the raw water are its bacteriological and hardness level. Analysis on the quality of liquid waste was done discover whether the hotel liquid waste can still be categorized align with the government standard in the disposal to the surrounding environment. Based on the result of hotel raw water analysis, five samples have aligned with the clean water standard, which is possible to categorized as clean water; while for the analysis of hotel liquid waste, the parameters used are turbidity, pH, BOD, COD and bacteriological test. The analysis shows that four hotels have exceeded the reasonable level of waste, where scheduled surveillance is required in keeping the environment away from waste disposal.
Chemistry students’ cognitive structures in oxidation-reduction, through an 8E learning cycle
Authors: Rahmawati Y , Ridwan A , Faustine S , Auliyani C N , Kartika I R , Rafiuddin R 
Published: December 2019

Abstract
The purpose of this study was to analyse students’ cognitive structure in the concept of oxidation reduction by employing an 8E learning cycle model. 32 students in year-10 were participated in the study. Data was collected by a drawing and writing technique demonstrated through student worksheets, interviews, observations, and a reflective journal. The 8E learning cycle, which consist of engage, explore, e-search, elaborate, exchange, extend, evaluate and explain stages, was applied to the process. Data analysis consisted of data reduction, data presentation, and a conclusion. Students’ cognitive structures were divided into three categories, namely; an understanding, misconception and no understanding. Categories of understanding were found in the concept of redox, oxidizing agents and acid-base nomenclature, and transitions. Students’ misconceptions of categories were found in the redox applications and polyatomic. Students faced challenges in understanding the oxidation number and binary nomenclature. The results show that misconceptions were decreased through the implementation of the 8E learning cycle. The 8E Learning cycle also has implications for students’ critical thinking, collaboration, and empathy communication skills.
Problem-based learning tools oriented of green chemistry in reaction rate concept
Authors: Fauziah N , Andayani Y , Hakim A 
Published: December 2019

Abstract
The aims of the study to produce and discover the quality of problem-based learning tools oriented to green chemistry in the reaction rate concept. Learning tools consists of the syllabus, lesson plan, student worksheet, modules, and test instruments. This research and development adapted Nieveens model which consisted of four stages: preliminary research, prototyping stage, summative evaluation, and reflection and documentation. The quality of the learning tools developed was measured through the analysis of validity and practicality. Product validity assessment used validation questionnaires distributed to experts, the data obtained were analyzed by using the content validity formula. Practicality used response questionnaires assessed by teachers and students, and the implementation of learning was analyzed by using a percentage of practicality. This study resulted in the average of content validity being 0,67 categorized valid. The practicality percentage of each aspect is 90,87%, 80,06%, and 80,56% categorized highly practical. The concluded that learning tools developed fulfills the criteria for developing quality products that are valid and practical.
Variations of binding, washing, and concentration of imidazole on purification of recombinant Fim-C Protein Salmonella typhi with Ni-NTA Resin
Authors: Nurjayadi M , Afrizal R , Hardianto D , Agustini K 
Published: December 2019

Abstract
Typhoid fever is an endemic disease in Indonesia. Prevention of typhoid fever can be done by administering vaccines. It is known that one of the raw materials for vaccines is a recombinant protein. This study aims to obtain information on the optimum conditions for purification of Salmonella typhi Fim-C recombinant protein with Ni-NTA resin as vaccine raw material. The three main stages of the purification process in this study were binding, washing, and elution of S. typhi Fim-C recombinant proteins. The binding and washing variations of recombinant proteins were carried out twice, four times and six times, while the elution process was carried out at imidazole concentrations of 200 mM, 250 mM, and 300 mM. Purification with a binding process four and six times gave almost the same intensity of S. typhi Fim-C protein bands. Whereas protein was elution at an imidazole concentration of 300 mM showed higher band instability. The results of characterization using SDS-PAGE and analysis using software ImageJ gel analysis showed that the longer the incubation time and the repetition of the binding process, the more protein bound to the resin. Furthermore, the more washing processes are obtained the purer proteins. Based on the data obtained it can be concluded that the purification of the S. typhi Fim-C recombinant protein was optimum at a four-time binding process, six times washing and a 300 mM imidazole concentration. These results are expected to be the basis for recombinant protein refining on a pilot scale and industry scale in better vaccine preparation.
Make it real: Simulation of 3D molecules using Augmented Reality in chemical bonding topic
Authors: Fitriani E , Suhartono S , Mugiarti I 
Published: December 2019

Abstract
The chemical bonding is one of the crucial topics in chemistry as it becomes a basic concept to comprehend other topics. Unfortunately, it is difficult for students to understand because it is at the submicroscopic level. This study proposes a way to comprehend that topic by developing a simulation of 3D molecules using Augmented Reality (AR). The data was collected by questionnaire. This study was used ADDIE procedure to develop the product. From the results of this study, it can be concluded that the Augmented Reality learning media has a very good quality and is worthy of being used as a supporting media in chemical learning activities in the chemical bond topic.
Constructing a simple electrolyte conductivity meter for chemistry learning
Authors: Hafimiyah D , Sukmawardani Y , Sundari C D D , Farida I 
Published: December 2019

Abstract
This research is based on the idea of the need for an innovative experimental learning media in the study of physical chemistry on electrolyte solutions conductivity concept. Through Research and Development method with the stages of analysis, design and development, a simple electrolyte conductivity measurement device has been produced. Based on the results of the research, the product was obtained in the form of an electrolyte solution conductivity measuring device that equipped with a user guidebook and an experimental worksheet of the electrolyte solution conductivity measurement. The electrolyte solution conductivity device is designed to measure the conductivity of an electrolyte solution. This measurement device is able to compare the conductivity value of fruit juices, vegetable juices and isotonic drinks quantitatively based on Kohlrausch’s law with simple and easy devices and materials. The validation result shows that the product is valid. The product was tested to chemistry education students using a feasibility test instrument. The result shows that the average of the value of the feasibility test is 93.85%. These results indicate that the constructed electrolyte conductivity meter is feasible to be used.
Development of mobile learning on acid and base to improve student performance
Authors: Cahyana U , Yusmaniar Y , Zahari P A 
Published: December 2019

Abstract
The aim of this research is to (1) make a Mobile Media Learning on Acid and Base and to determine the quality of the media produced, (2) determine the feasibility of the media used in learning process. The subjects of this research were students of 54 Senior High School Jakarta, 42 Senior High School Jakarta, and 7 chemistry teachers. The research was conducted from January to May 2018. The method used in this research is Design-Based Research. The steps performed in this research are: (1) needs analysis, (2) developing mobile learning, (3) validation test of mobile learning media, (4) media testing by students and small scale of teachers, (5) media trials by students and teachers on a large scale. The results obtained from expert validation tests, small class trials, large class trials, and effectiveness of the media, it can be concluded that the mobile media learning developed in this research is good enough to use in the learning process. The n-gain value obtained from the effectiveness test is 0.76 which can be categorized as high effectiveness, based on the Paired t-test the Tcount value is 28.048. The paired t-test value is Tcount>Ttable (2.03), so it can be concluded that there is a significant difference between pre-test score and post-test score. That difference means that there is improvement in students average score after using the mobile media learning.
Development of mobile game base learning on buffer solution to improve student performance
Authors: Cahyana U , Paristiowati M , Pratiwi W E , Zahari P A 
Published: December 2019

Abstract
This study aims to develop innovative learning media that is Mobile Learning and know the quality of media produced and know the feasibility of media to be used in learning on buffer solution. This research was conducted at 107 Senior High School Jakarta and 42 Senior High School Jakarta starting in January 2018 until May 2018. The research method used is Design-Based Research which includes 4 stages, namely: (1) needs analysis, (2) development of mobile learning media, (3) Feasibility and trial test. Mobile learning media that generates an app on Android-based smartphones (smartphone) called “ChemBuff” is 167 MB compatible on Android devices up to v.7.1 Nougat with features such as material, video and educational features about the solution buffer. Based on the feasibility test results and the small scale and large scale effectiveness tests, it can be concluded that the mobile learning media is feasible and effective. The result of the effectiveness test shows that there is a very significant difference between the pre-test and post-test value as well as an increase in the average learning outcomes of learners after using mobile learning media buffer solution. The resulting media test can improve student learning outcomes.
Synthesis of silicalite-1 zeolite using silica from elephant grass (Pennisetum purpureum)
Authors: Sundari C D D , Setiadji S , Andriani A , Sumiyanto E , Ivansyah A L 
Published: December 2019

Abstract
Silicalite-1 is a type of zeolite with no aluminum content and is hydrophobic. This zeolite can be synthesized from various types of silica. Elephant grass (Pennisetum purpureum) is one of the potential agricultural wastes that has a fairly high silica content that can be used for zeolite synthesis. In this study, silicalite-1 zeolite was synthesized using silica extracted from elephant grass and tetrapropylammonium bromide (TPABr) templates. Silica samples extracted from elephant grass have 71.91% amorphous SiO2 content. Silicalite-1 zeolite was synthesized with molar ratio of 1SiO2 : 0.527TPABr : 0.395Na2O : 98.45 H2O, using hyrothermal method at 180°C for 24 hours in a stainless steel-teflon lined autoclave. The resulting silicalite-1 samples were confirmed by X-Ray Diffraction (XRD) and showed 2θ which was typical for silicalite-1 i.e. 8.02°, 8.93°, 23.09°, and 23.98°. The results of Scanning Electron Microscopy (SEM) show that silicalite-1 zeolite has hexagonal crystals with 43.36 µm size as a result of the calculation using the Schrerrer method.
Identification of glibenclamide in antidiabetic jamu by high performace liquid chromatography method: Study in Purwokerto, Indonesia
Authors: Utami P I , Firman D , Djalil A D 
Published: December 2019

Abstract
Adulteration of synthetic pharmaceutical drugs in jamu is prohibited by law in Indonesia. Glibenclamide is one of the drugs commonly added to antidiabetic jamu. The purpose of this study was to obtain a valid high performance liquid chromatography (HPLC) method for qualitative and quantitative analysis of glibenclamide in antidiabetic jamu. HPLC separation was carried out with a Kromasil 100 C18 column (150 x 4.6 mm i.d, 5 μm particle size) using methanol: water (75:25) v/v as the mobile phase at a flow rate of 0.5 mL/min, UV detection was set at 301 nm. There was no potential interference from other compounds at the glibenclamide retention time (retention time of 5.234 ± 0.056 minutes). The method has good linearity (r = 0.9936) in the range 10-50 µg/mL. The detection limit of the method was 6.21 µg/mL while the quantitation limit was 20,71 µg/mL. The relative standard deviation (RSD) of intraday precision was 0.85%. The average recovery using standard addition method was 100.63 ± 13.71%. The application of the HPLC method for the analysis of five antidiabetic jamu samples obtained from the market in Purwokerto showed that glibenclamide was detected in one sample with a level of 1.88 ± 0.25 µg/g.
Formulation of facial cleansing gels using aloe vera as natural surfactant
Authors: Wulandini R , Irwansyah F S , Windayani N 
Published: December 2019

Abstract
This study aims to make facial wash gel made from Aloe vera as a natural surfactant. The design based research experimental method used includes the phytochemical screening analysis of samples of A. vera extract, making A. vera gel with the addition of carbomer 960 to the aloe extract solution with a percentage of 0.5%, 0.7% and 2%, selection of essential oils according to the needs of facial skin. Furthermore, making Aloe gel as a facial wash by adding carbomer 960 with a percentage of 0.5%, 0.7%, 2% then add triethanolamine to alkalinize the A. vera extract to form a stable gel according to the characteristics of the Indonesian national standard (SNI 2588:2017). This facial wash utilizes secondary metabolites contained in A. vera. The results showed that A. vera extract used positively contained flavonoid, triterpenoid, saponin and polyphenol compounds. The best formulation of facial wash gel has been successfully obtained from the addition of carbomer 960 with a percentage of 0.7%, triethanolamine eight drops, moringa seed oil 1ml, virgin coconut oil 1ml, one drop of lavender oil, whey kefir five drops, and natural E 2 capsules. The organoleptic results of A. vera gel as facial wash include having an aroma following the added essence, soft texture, gel form, cloudy white color, feeling relaxed or cold when applied to facial skin, and without foam having a pH of 5 according to SNI.
The effect of concentration and temperature on the activities of Polyethylene Oxide (PEO) as iron corrosion inhibitor in electrolyte solution of NaCl
Authors: Sudiarti T , Silviayanadewi A Y , Supriadin A 
Published: December 2019

Abstract
Internal corrosion in the piping system is a serious problem. The use of corrosion inhibitors for corrosion control in piping systems is a practical and cost-effective method. Many polymers have been reported to be used as an inhibitor corrosion. However, there was little attention to the research of Polyethylene Oxide (PEO) as a corrosion inhibitor in NaCl medium. The purpose of this study was to determine the corrosion inhibition activity of polymeric compounds of polyethylene oxide against ferrous metals in 1% NaCl electrolyte solution. The study of Polyethylene Oxide (PEO) activity as a corrosion inhibitor in 1% NaCl electrolyte solution was carried out by the Wheel Test method with variations in concentration and temperature. The surface analysis of iron by SEM (Scanning Electron Microscopy). The results showed that polyethylene oxide (PEO) had the optimum inhibitory activity at a concentration of 16 ppm, with inhibition efficiency of 80.15% at 25°C. Polyethylene Oxide has adsorption properties which are in accordance with the Langmuir adsorption isotherm with free adsorption energy of -21.385 kJ / mol. The results of the surface analysis by Scanning Electron Microscopy (SEM) showed that polyethylene oxide could inhibit corrosion rates with iron surfaces that had fewer pores than without inhibitors.
Chemical changes coconut oil in different fermentation during long time storage
Authors: Janurianti N M D , Sudiarta I W , Situmeang Y P 
Published: December 2019

Abstract
This research aims to know the old fermentation influence the chemical changes during storage on coconut oil. Coconut oil is made with fermented pineapple extract as much as 15%. Coconut oil characteristics compared with the standard National Indonesia No. 01-2902-1999. This research was carried out in the laboratory of Food Analysis Faculty of Agriculture Warmadewa University. This study is a Randomized Design with factorial experiment complete consisting of two factors, namely: factor I, long fermentation that consists of 3 levels, namely 12 hours, 24 hours and 36 hours. Factor II, long storage that consists of 4 levels, namely 0, 1, 2 and 3 weeks. The observed variables against the coconut oil include objective observations i.e. water content, free fatty acids, peroxide, levels of dirt and acid number. The characteristics of coconut oil during storage tend to change but still meet Indonesian National Standard No. 01-2902-1999. From the results of research on the long fermentation 12% with prolonged storage 0 weeks gives the characteristics of the best oils than any other treatment that is the average value of water content, the level of dirt, free fatty acids, peroxide and acid number respectively i.e. 0.17%, 1.56%, 0.53%, 1.45% and 2.20%. During the storage of chemical changes tend to occur on coconut oil. The value of the average water content, the level of dirt, free fatty acids, peroxide and acid number highest obtained on treatment of fermentation 36 hours and long storage of 3 weeks in a row with a value of 0.50%, 3.70%, 0.85%, 2.51% and 4.38%.