bluuebunny/crossref_metadata_2025_split huggingface dataset:
Application of the contextual teaching and learning model as an efforts to improve student results and scientific performance of student physics
Authors: Arygunartha G Y , Situmeang Y P 
Published: December 2019

Abstract
This study aims to improve student learning outcomes and scientific performance of physics. This research is a classroom action research. Subject from this study were students in the semester an odd number of school year 2018/2019 as many as 19 male students. This research implemented in two cycles with each cycle stage consisting of planning, action, observation/evaluation, and reflection. The results of this study indicate that 1) there is an increase in students’ scientific performance. In the first cycle, the average value of performance the scientific achievement of students is 77.37 with a fairly high category, while at the second cycle increased to 87.90 with a very high category, 2) an increase student physics learning outcomes. In the first cycle, the average value of physics learning outcomes is achieved students are 73.00 while in cycle II it increases to 77.50. Research This class action is categorized as successful because it has reached the level of completeness Hornax of 94.7%.
Implementation of OPTIKU pocket book based Android for enhancing problem solving ability
Authors: Mulhayatiah D , Fitriyanti N , Setya W , Suhendi H Y , Nasrudin D , Malik A 
Published: December 2019

Abstract
Problem-solving ability is one of the abilities that must be possessed by students in the 21st century. Field studies obtain data that some students have low problem-solving abilities. This study aims to determine the feasibility of learning, improvement of problem-solving abilities, and differences in problem-solving abilities of students between classes using Android-based pocketbook learning media with classes that do not use Android-based pocketbook learning media on optical instrument concept. The method used in the study was a quasi-experiment with the design of a non-equivalent control group. The sample was selected using a purposive sample technique. The results showed that the implementation of learning was classified as a good category and there were differences in the problem-solving abilities of the two classes of students because the N-gain experimental class was 0.63 and the control class was 0.53. This shows that Android-based pocketbook learning media can improve students’ problem-solving abilities in the optical instrument concept.
Kalman filtering to real-time trace water level measurements using ultrasonic sensor
Authors: Iswanto B H , Parmono I F , Delina M 
Published: December 2019

Abstract
Water level monitoring systems are needed in various related fields. However, to accurately determine water levels typically difficult due to the effect like sloshing in dynamic environments. In this paper, we proposed Kalman filter based approach to reduce uncertainty in the water level measurements. Experiments have been performed by filling the tank with water and installing an ultrasonic sensor module at the top center of the tank. The water tank is vibrated with an artificial vibrator, then measuring the water level is done by the ultrasonic sensor. To reduce measurement errors we introduced the Kalman filtering. This technique is developed for improving the precision of water level measurements in the presence of various noise sources. The Kalman filter performance is demonstrated to be adaptive to real-time noise. Experiment results indicate reducing the errors of measurement significantly up to about 60% for a dynamic water condition by adjusting appropriately the Kalman filter tuning parameters.
Band gap control of bilayer zigzag graphene nanoribbon by direction of magnetic moment
Authors: Prayitno T B , Budi E , Fahdiran R 
Published: December 2019

Abstract
We have demonstrated the first-principles calculation to tune the band gap of the bilayer zigzag graphene nanoribbon by arranging the direction of the magnetic moments of carbon atoms at the edges. These directions were specified by the polar angle, as defined in the spherical coordinates. From the ferromagnetic configuration to the antiferromagnetic configuration, as the polar angle increases, the band gap increases. We also showed that the ferromagnetic configuration leads to the metallic system while the others lead to the insulator, in a good agreement with the previous calculations. These results indicated that the bilayer zigzag graphene nanoribbon is potential for the spintronics devices.
Dilated cardiomyopathy with long QT secondary to hypothyroidism and hypocalcaemia in patient with post total thyroidectomy: A case report
Authors: Yudistira K A , Pranata I G B , Bagiari K E 
Published: December 2019

Abstract
The linkage between cardiac dysfunction and the lack of thyroid hormones has been well elucidated. A case involving a woman aged 44 years suffering a dilated cardiomyopathy (DCM) and long QT secondary to hypothyroidism and hypocalcaemia emerges. Thyroid hormone acts on the myocardium of the heart and peripheral blood vessels. There are two types of thyroid hormone effects, such as genomic and non-genomic. These effects are associated with cardiovascular and hemodynamic function. The prolongation of the QT interval is the most overlooked and well-documented sign in hypothyroidism. Ventricular fibrillation is usually the leading factor for the long QT syndrome. The incidence is characterized by an increased risk of sudden death and the abnormal QT-interval prolongation on the surface of ECG. The mechanism of hypothyroidism on the occurrence of the ventricular tachycardia and the OT prolongation is unrecognized, and although coexistent, the effects might be distinctive.
Fouling resistance study of poly (ether sulfone) ultrafiltration membrane which in-situ polymerized with polydopamine
Authors: Meirisa F , Muchtar S , Arahman N , Mulyati S 
Published: December 2019

AbstractThis works focuses on the fouling resistance evaluation of polydopamine-blended poly (ether sulfone) (PES) ultrafiltration membrane for water treatment application. The supporting PES membrane was prepared via a common phase inversion method. The dopamine was introduced to the membrane by blending technique and the modification occurred by in-situ polymerization of dopamine into polydopamine which triggered by peroxide. The antifouling performances were studied in terms of flux recovery, reversible fouling, irreversible fouling, and total fouling. The relevant characteristics of the membranes such as surface porosity, chemical composition, water permeation, and solute rejection were also provided to support the analysis of antifouling performances. The results revealed that the presence of polydopamine in the membrane system significantly enhanced the fouling resistance of the polydopamine-blended PES membrane. The hydrophilic component in polydopamine reduced the interaction of membrane with foulant thus lowered the total fouling of only 18.92% with 13.50% reversible fouling and 5.42% irreversible fouling for modified membrane. In addition, the polydopamine-modified membrane successfully recovered up to 95% of the flux after backwashing, much higher than that of original PES which was only 67%.
Removal of Fe (II) in groundwater using rice husk-sourced biosorbent in continuous column adsorption
Authors: Maliki S , Rosnelly C M , Adisalamun A , Husin H , Bilqis N 
Published: December 2019

Abstract
Ferrous is one of the groundwater contaminants that negatively impacts health and the environment. The allowed ferrous content is < 1 ppm in water for daily use. Removal of Fe in groundwater by adsorption using low-cost bio-sorbent from rice husk has been conducted. The process was carried out in continuous mode using two types of rice husk-sourced adsorbents, one was only carbonated at 400 C and another was followed by a physical activation at 650 C. To study the effects of physical activation on the surface characteristics, both types of biosorbents were characterized by Scanning Electron Microscope and Fourier-transform infrared spectroscopy. The concentration of artificial sample before and after adsorption was evaluated using the Atomic Absorption Spectroscopy. From the results, the adsorption using physically activated sorbent had greater removal efficiency of 74.02% compared to that of without activation treatment, which was only 65.70%. In addition, the concentration of ferrous was successfully reduced to 1,029 and 0.779 ppm from the initial concentration of 3 ppm for the process using the adsorbent without and with activation, respectively. It can be concluded that the physically activated rice husk has the potential to be used for adsorption of Ferrous in continuous column.
Enhance photocatalytic of hydrogen production from water-glycerol solution over RuO2-loaded
Authors: Husin H , Pontas K , Zaki M , Darmadi D , Masna A 
Published: December 2019

AbstractStudy of hydrogen production from aqueous glycerol solution on RuO2-loaded LaNaTaO3has been studied. This research aim is to investigate the influence of co-catalyst RuO2and glycerol as a sacrificial reagent on the photocatalytic process of hydrogen production. La-doped NaTaO3was prepared via sol-gel route. The RuO2was loaded onto the LaNaTaO3surface by impregnation method. The sample was characterization by Scanning Electron microscopy (SEM) and X-ray Diffractometer (XRD). From XRD spectrum shows that the La-NaTaO3photocatalyst has high crystallinity. The SEM analysis indicates that the size of La-NaTaO3photocatalyst is ranging from 100 to 250 nm without agglomeration and RuO2as a co-catalyst is well loaded into the La-NaTaO3surface. The rate of hydrogen production increased significantly with a glycerol concentration. Loading RuO2on La-NaTaO3photocatalyst is proved to increase the rate of hydrogen production of 3.2 times with the addition of glycerol as a sacrificial reagent. The highest hydrogen production activity was obtained for 0.3 wt.% ruthenium loading. The role of co-catalyst RuO2and glycerol as a sacrificial reagent has enhanced the performance of La-NaTaO3photocatalyst since both play an active role in the separation efficiency of electrons and holes and the reaction of hydrogen formation.
Initial screening of AOS, its performance in EOR to improve oil recovery
Authors: Pratiwi R , Setiati R , Andryan R , Fadliah F , Fajarwati K 
Published: December 2019

Abstract
Continuous increasing of fuel need in Indonesia, at least in the last ten years, is the reason for improving domestically crude oil production. Exploitation in the form of oil drainage activities needs to be investigated further. Surfactants as an agent that believed can reduce interfacial tension, need to be determined the formulation and compatibility in their use for oil drainage from reservoirs. Screening of the conditions of surfactant operation needs to be done in order to provide optimal oil recovery. In this study a surfactant behavior test was carried out on AOS (Alpha Olephin Sulfonate) in a laboratory scale, using sandpack as a sandstone reservoir rock prototype, measured the effect of salinity and concentration on oil recovery in chemical flooding, where interfacial tension (IFT) as the main variable. From the measurements, it was found that a surfactant concentration of 1.5% worked optimally in formation water with a salinity of 10,000 ppm, by producing IFT of 16,75 mN/m and recovery factor of 7.5%. This is compatible with the properties of AOS surfactants which can work well in solutions with low salinity The emulsion formed shows that the surfactant works in the upper phase, or tends to dissolve in oil, correlates with the basic ingredients of surfactant which is an oil base.
Laboratory study on the effect of salinity, surfactant type and concentration to recovery factor for carbonate rock
Authors: Yulia P S , Kasmungin S , Fathaddin M T 
Published: December 2019

Abstract
The needs of petroleum as energy, have increasing while the oil production has depleting. Due to that needs, the method of Enhanced Oil Recovery (EOR) or in other hands as tertiary recovery (after primary recovery and secondary recovery) is being developed. EOR has many methods; one of the methods is chemical injection that consists of surfactant, alkaline and polymer. In this experiment, the author is using surfactant injection. The using of surfactant is to decrease the interfacial tension between oil and water, with the result is surfactant can displace oil through rock pores. This study will be discussing about the effect of salinity, surfactant types and surfactant concentrations on surfactant injection for carbonate rock. The surfactant types are Alpha Olefin Sulfonate (AOS) and Tween 20. The surfactant concentration varieties are 0,1%; 0,25%; 0,5%; 0,75% and 1%. Salinity varieties are 10.000 ppm; 15.000 ppm; 20.000 ppm and 25.000 ppm. From this study, it had determined that surfactant can displace the oil from rock pores based on the influence of salinity, surfactant concentrations and surfactant types to recovery factor. The determination of recovery factor will be using these methods; Amott apparatus (imbibition process) and injection using core holder and syringe pump. From experiments that have been done, the effect of surfactant injection on carbonate rocks is more optimal in core flooding process compared with imbibition process, with the recovery factor percentage is 57%. Core flooding process uses the external thrust, therefore the oil displacement with surfactant is more evenly and optimally.
The effect of concentration of Ceremai (Phyllanthus Acidus) Fruit extract on FH (Friesh Holland) cattle milk clumping in cheese making
Authors: Mulyani L S , Ardiana C , Kurniasih N , Hernawati D , Rohayat A 
Published: December 2019

Abstract
Most of the milk consumed by humans comes from cow’s milk. The processed products are cheese as a result of the separation between whey and curd through the fermentation process. This process involves microbial activity that takes place in aerobes and anaerobes. Making cheese involves the process of clumping milk with helping of the rennet enzyme. There are difficult to obtain and the price is relatively expensive. So that a replacement for this enzyme is needed. Ceremai fruit extract can be used in the process of milk clotting. The research aims to find the concentration of it which optimally influences the clotting process of FH (Friesh Holland) cow milk in cheese making from the time of clumping. It is obtained by blending until smooth, then poured into a filter and squeezed to get extract. The extract was used for 5 treatments with a concentration variation of 50%, 60%, 70%, 80%, and 90% with 5 repetitions. The results showed at the concentration of 90% produces the optimal clumping time with an average clumping time of 5.4 minutes. So influences the time of clumping of cow’s milk in making cheese and it can be used as an alternative ingredient for rennet enzymes.
Betung Bamboo Shoot (Dendrocalamus asper Backer ex Heyne) Extracts: Accelerating the growth of Java Apple (Syzygium samarangense) stem cuttings
Authors: Mulyaningsih S , Sumiati D , Hernawan H , Robbiyani R , Sriwahyuningsih S 
Published: December 2019

Abstract
The pruning waste of Java Apple (Syzygium samarangense) tree branch can be used for its propagation by stem cuttings. The rooting process can be accelerated with the help of growth regulators, one of which is betung bamboo shoot extract. Using a randomized block design, this experiment aims at examining the effect of betung bamboo shoot extract with concentrations of 0%, 10%, 20%, 30%, 40% and 50% on the growth of Java Apple stem cuttings. The samples were 48 stem cuttings with a diameter of 1 cm and a length of 15 cm. The results showed that betung bamboo (Dendrocalamus asper) extracts could accelerate the propagation process. The optimum concentration was 50%.
Potential amylase-producing yeast isolated from indigenous fermented beverages originating from Bali, Indonesia
Authors: Sukmawati D , Arman Z , Sondana G A , Fikriyah N N , Hasanah R , Afifah Z N , Balqis M , Enshasy H E , Husna S N A , Rahayu S , Kurniati T H , Puspitaningrum R 
Published: December 2019

Abstract
Indonesia has many fermented beverages, and yeast become one of the agents in fermented process. Yeasts has a role to transform carbohydrate complex into simple compounds with release secondary metabolism to environment like amylase enzyme. This study aims to get the isolate of yeast that can potentially produce amylase enzyme. This research conducted in October 2018 until March 2019 in Microbiology Laboratory of Universitas Negeri Jakarta. The screening test of potential isolate producing amylase enzyme was performed on yeast isolate from eight source of indigenous fermented beverages that can grow in YMA medium with pH 2. Screening was carried out on YPSA medium with diffusion agar method. From 50 Isolates, 16 isolates with the codes IB4, IB15, IB20, IB21, IB26, IB36, IL78, IL80, IL81, IL86, IL88, IL97, IL113, IL136, IL146, and IL150, were able to form clear zone after 1-day incubation in room temperature. The highest amylolytic index was produced by IL86 (1,019 mm). Forming the clear zone is proof that yeast can transform starch become simpler sugar like maltose as iodine-starch reaction is resulting amylose helix and iodine become I3
− that filled main core helix. In addition to this, iodine forms complexes with starch molecules showed a dark purple colour.
Performance of 0-14 weeks-aged super free-range hens that are fed by fermented coconut pulp flour-contained ration
Authors: Suwitari N K E , Suariani L , Yudiastari N M , Kaca N , Tonga Y 
Published: December 2019

Abstract
The research was carried out at the Basic Laboratory of the Faculty of Agriculture, Warmadewa University with a level of use of fermented coconut pulp, namely R0 (ration that contains no fermented coconut pulp, R1 (ration containing 5% fermented coconut pulp flour), R2 (ration containing 10 % fermented coconut pulp) and R3 (rations containing 15% fermented coconut pulp). Each combination of treatments was repeated three (3) times, and each replication consisted of 4 super female free-range chickens. Variables observed included: 1). Age of chicken growth includes the weight gain and final weight of super free-range chicken, 2) Percentage of carcass and non-carcasses for super free-range chicken, 3) Feed Conversion Ratio (FCR, and 4) Feed consumption. From this study it was found that the giving of coconut pulp flour was fermented up to 10% (R2) significantly (P<0.05) could increase weight gain and final weight and flour dregs fermented coconut to the level of 10% also decreases ration consumption and the conversion of ration for super female chicken 14 weeks old.
Design of educational games oriented to chemical literacy on petroleum material
Authors: Sari S , Safitri I , Farida I 
Published: December 2019

Abstract
This study uses the stages of the Research Based Design method to produce an educational game oriented to chemical literacy on petroleum material. This research is driven by the importance of a visual learning media in order to improve the ability of chemical literacy in petroleum material so that students can connect between knowledge of concepts and phenomena that occur. The aim of the study is to describe the appearance of educational games oriented to chemical literacy on petroleum material. Based on the results of the study, it is obtained that the chemical literacy-oriented educational game products in the form of chemical monopolies and chemical energy ladders which have characteristics such as game rules that modify the monopoly and snake ladders games equipped with questions oriented to chemical literacy, obstacles in the games show the levels of difficulty and levels of thinking as well as different visualizations that illustrate the context and application of petroleum.
The making of metal coating props oriented chemical representation
Authors: Mayangsari D , Irwansyah F S , Farida I 
Published: December 2019

Abstract
The purpose of this research is to produce metal coating props that oriented to chemical representation and find out the results of validation and feasibility of the props that has been made. This research used research and development method with stages of analysis, design and development. Based on the results of this research, the product is obtained in the form of metal coating props with the characteristics of combining macroscopic, submicroscopic and symbolic representations with guidebooks and worksheets. Validation results indicate that the product is valid with the acquisition of the value of rcount on props of 0.93. The results of feasibility tests conducted on 3rd grade of 27 Senior High School Bandung showed that props are very feasible with the percentage of successive value of 97%. High validation and feasibility values are caused by props that have met the criteria as a good medium and in accordance with metal coating material. The impact, the resulting props can be used as a medium that can help students gain a complete understanding of the concept of metal coating.
Rosa sp and Hibiscus sabdariffa L extract in ethanol fraction as acid base indicator: Application of green chemistry in education
Authors: Paristiowati M , Moersilah M , Stephanie M M , Zulmanelis Z , Idroes R , Puspita R A 
Published: December 2019

Abstract
Green Chemistry principal was introduced in an academic environment in the 1980s as guidelines for sustainable development focused on chemistry. Efforts to realize these expectations can be applied through education by developing learning process based on environmental. This study aims to apply the concept of Green Chemistry in education, especially chemistry learning by producing natural acid-base indicators from the extract of roses (Rosa sp) and Rosella (Hibiscus sabdariffa L). These indicators are produced by the method of extraction using 96% ethanol solvent in an acidic atmosphere at pH 3-4. The results of maceration then extracted in three different solvents (ethanol, n-hexane, and chloroform). The extract was tested in solution with pH 1-12 and used as an indicator to identify the solutions and titration in acid-base topic. It concluded that the roses and Rosella can be used as an alternative raw material for acid base indicator. The use of roses and Rosella indicates an attempt to have applied the principles of green chemistry, including the prevention of the formation of hazardous wastes, the design of safe chemical products, the use of renewable materials, the design of materials that are easily degraded, and the use of safe solvents.