bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interpretation of Conventional Reciprocal Method (CRM) refraction data for identification of subsoil structure in the tourism area at Batu Kuda Bandung
Authors: Nurasiah S , Muhammad F H , Agustina R D , Sugilar H 
Published: December 2019

Abstract
The purpose of this study is to identify the subsurface geological structure by using the seismic refraction method in the Wana area of Batu Kuda tourism using Seismic Data Interpretation Refractive Conventional Reciprocal Method (CRM) which aims to produce a GUI. Data obtained in the form of wave propagation time as time forward and time reverse, from the travel time of the wave and distance and time geophone analysis. From the results of the data interpretation, the velocity of P wave propagation in the medium and depth is obtained in 2 layers. In the first layer obtained a velocity value of 628.98 m / s with the depth of the first layer ranged from 0 m - 8.73 m and the seismic wave velocity in the second layer was 1228.99 m / s with the depth of the second layer ranged from 8.73 m - 20 m. Based on the 2D model the distribution pattern of velocity values, it can be indicated that the first layer is the latosol soil layer containing sand, gravel, fine sediment and clay. The second layer contains fine deposits, sandstone, gravel, sand, fine sand (silt), clay and clay. These materials as a result of the process of the eruption of an undefined young volcano.
Theremin as teaching aid to improve student understanding of waves
Authors: Ambarwanti D , Astra I M , Yaqin A A , Sugihartono I 
Published: December 2019

Abstract
Physics learning is taught to equip students with knowledge and understanding of various natural phenomena. In order to improve comprehensive understanding of waves principle for student class of XI, we implement science, technology, engineering, and mathematics (STEM) in physics learning by using theremin based light dependent resistor (LDR). In this paper, theremin as music instrumental non-contact will be used as teaching aid. Physics understanding of the students will be observe and investigated during a class. Analyses will be focus on adjustment of frequency will provide pitch of tones. As results, by theremin, student will have better understanding of waves principles.
Development of Android-base media on the point of glass and lens
Authors: Setya W , Zakwandi R 
Published: December 2019

Abstract
Android gives a great revolution to the world of education to develop learning applications that facilitate its use to study anywhere and anytime. This study aims to make Android-based media using app-inventor on glass and lens material. The development of this media uses R & D (research and development) research and development methods which consist of 4 stages, namely the analysis phase, design stage, production stage, and evaluation stage. The results of using Android-based media have an average value of questionnaires from material experts, media experts, and small-scale trials categorized very well close to 50%. Based on these results it can be stated that the lens and glass media based on Android can be used as a medium of learning in the classroom. The development of this Android-Based Physics Application is expected to be an alternative for educational institutions or educators to develop learning media that use multimedia.
How is STEM learning for children with special needs in Indonesia?
Authors: Hudha M N , Triwahyuningtyas D , Rafikayati A , Fajaruddin S , Maryani I , Widiaty I , Nandiyanto A B D , Hamidah I , Permanasari A 
Published: December 2019

Abstract
This paper is a preliminary study aiming at discovering information on STEM learning for children with special needs in Indonesia. The method used in this study was descriptive qualitative using a questionnaire and interviews with teachers, parents, and students with special needs as the research instruments. It is concluded that the students needed more effective media in STEM learning.
Theoretical study on the effects of polarons on the transport properties of anatase TiO2
Authors: Bupu A , Majidi M A 
Published: December 2019

Abstract
We present a theoretical study on the effects of electron-phonon interactions on the transport properties of anatase TiO2. Temperature-dependent resistivity measurement on anatase TiO2 thin film has shown that carrier concentrations and temperatures affect the resistivity of this material. At low carrier concentrations, a metal to insulator transition could be observed, while at high carrier concentrations this material only shows metal-like resistivity. In this study we aim to investigate the behaviour of temperature-dependent resistivity at various carrier concentrations as revealed in the experimental study. We hypothesize that electron-phonon interactions with intermediate coupling constant govern the transport properties of this material. We construct Holstein model Hamiltonian incorporating both conduction and valence bands of anatase TiO2 within parabolic dispersion approximation. We solve the model within the Dynamical Mean Field Theory (DMFT). We calculate the density of states of the system and the corresponding inverse of the square of the density of states at the chemical potential, which is approximately proportional to the resistivity, as a function of temperature. Using carrier concentration values taken as in the experimental data, the calculations show that only insulating phase is found in the low carrier concentrations regime. Meanwhile, at high carrier concentrations, the results show metal-like properties, in agreement with the experimental data.
Effect of agility ladder exercises on agility of participants extracurricular futsal at Bina Darma University
Authors: Hidayat A 
Published: December 2019

Abstract
The purpose of this study was to determine the effect of agility ladder training on the agility of the student of the futsal extracurricular Bina Darma University Palembang. The research method used in this study is a quasi-experimental method. The design of the research design used in this study was one group pretest-posttest design. A sample of 24 people participated in the Bina Darma University futsal extracurricular activity. The technique of collecting data uses an agility test instrument, namely Illinois Agility Run. The element of agility is very dominant in helping students gain student fitness. Usually students who are fit are characterized by good physical condition (agility). Agility in students is very useful to develop students’ skills in any field of sports in general, and can help students master the physical education subjects related to agility. The results of the study revealed that the average score of agility pretest obtained by students was 19.05 seconds while for the average value of posttest (final ability test) student agility was 18.99 seconds. Normal and homogeneous distributed data because the results of the Kolmogrov Smirnov test and the data homogeneity test show that the large sig value is 0.05, so that it is continued with the paired t-test results obtained that the t-count value 1.930 is greater than the t-table 1.714 at a significant level of 0.05%. Thus it can be concluded that there is a significant influence agility ladder training for agility at participant’s futsal extracurricular Bina Darma University of Palembang.
Application foam agent to foam cement slurry for geothermal well drilling
Authors: Hamid A , Setiati R , Santoso A 
Published: December 2019

Abstract
One type of light weight cement is foam cement which can be used in cementing operations in weak zones with the possibility of small fractures and reducing the amount of light weigh cement suspension levels. The foam cement suspension can be used to solve lost circulation due to natural vertical fractures or cavernous formations. The purpose of this study was to determine the potential of foam cement slurry to solve the lost circulation in geothermal well. Making slurry cement uses class G cement at 200 mesh and 100 mesh size with the composition of cement. The cements put into the waring blender containing water stirit for 35 second, adding foam agent into cement slurry with variations in foam agent concentration of 0.03%, 0.06%, 0.09%, 0.12% and 0.15%. observations of foam cement above were carried out for 30 minutes to test the stability of bubbles in the mixture. The result this study showed different compressive strength values at variations the concentrations of foam agent. The strength value is strongly influenced by result of sample with 0.03% with Sika-aer concentration have a compressive strength value of 3745 psia, while sample with Sika-aer concentration of 0.15% have compressive strength value of 1701 psia. The value of compressive strength core foam cement can form a linear line according percentage foam agent concentrations. Foam agent between 0.03% - 0.15% with Sika-aer qualified the minimum requirements BHCT compressive strength according API-10B rules to reduce severity lost circulation in the well X-E2 in geothermal drilling well.
The effect of β-Carotene (C40H56) in Carrots (Daucus Carrota) as a natural additive substance for wet noodle durability
Authors: Rohayat A , Ardiana C , Nurkhotimah R , Hernawati D , Mulyaningsih S 
Published: December 2019

Abstract
Additives are chemical compounds added to maintain food including wet noodles. The durability of wet noodles is relatively lower compared to other staple foods. There are many ways to preserve wet noodles, one of which is natural additives. Natural additives are chosen because they are safer and do not pose a risk to human health. Substances Natural additives used are carrots (daucus carrota). Because carrots contain β-Carotene compounds that function as antioxidants. Where can reduce and deactivate free radical attacks and ROS (Reactive Oxygen Species) to foods caused by microorganisms. The study aims to influence the content of β-Carotene in carrots as a natural additive for the resistance of wet noodles. The research method used was an experiment with variations in the concentration of β-carotene in carrots 0%, 20%, 40%, 60%, and 80%. From the results of the study it was found that at the β-Carotene concentration of 60%, the durability of wet noodles reached a maximum of 4 days. This fact shows that the addition of β-Carotene with high concentration will affect the durability of wet noodles. So that shows that carrots (daucus carrota) can be used as natural additives in maintaining the durable power of wet noodles.
Antioxidant capacity of Dillenia sp. leaf extract against DPPH (1,1-Diphenyl-2picryl Hidrazil) radical
Authors: Rahayu S , Zahara I , Afifah A , Arya P K , Supriyatin S 
Published: December 2019

Abstract
Some plants have capacity as exogenous antioxidant. Simpor (Dillenia sp.) is plant of the Dilleniaceae family which may have the property of antioxidant. The purpose of this study was to measure the antioxidant capacity of the 96% ethanolic simpor leaf extract. Factorial design was applied with 2x3 factors of maseration time (24 and 48 hours) and concentration series of (10, 15, 20%). Normality was done by Kolmogorov-Smirnov and homogeneity by Levine. Data was analysed by ANOVA (ᾳ = 0.05). Post Hoc was analysed by Duncan. Antioxidant property was analysed qualitatively and quantitatively on flavonoid and also leaves water content. The antioxidant capacity assay was measured using DPPH (1,1-Diphenyl-2picryl Hidrazil) scavenging ability at 517 nm with ascorbic acid as control. The result showed that water content of the plant was 73.65%. Simpor contain flavonoids with highest flavonoid content (2.953 mg QE / mg) in 24 hours maceration time at 15% concentration. Furthermore, it also has ability to scavenge DPPH (1,1-Diphenyl-2picryl Hidrazil) radical with the highest value (97,10 ± 0,01%) in 24 and 48 hours maceration at 20% and 10% extract concentration. Statistical analysis on flavonoid content showed that time and concentration gave significant effect on flavonoid content (ᾳ = 0.003). Duncan result revealed that almost all groups didn’t significantly different only the 24 hours x 15% concentration was. DPPH inhibition based on statistic proved that both factors didn’t affect scavenging ability of Dillenia (ᾳ = 0.079). It can be concluded that simpor leaves has antioxidant capacity against DPPH radical due to its flavonoid content. Furthermore, concentration and maceration time significantly affect flavonoid content and didn’t affect DPPH radical scavenging ability of Dillenia plant.
Chlorpyrifos organophosphate and essential oils activities against Callosobruchus maculatus (F.) warehouse pests
Authors: Subekti N , Nur H , Fanidya A , Susanti S , Saputri R , Indrawati P 
Published: December 2019

Abstract

Callosobruchus maculatus (F.) is a warehouse pest causing damage to foodstuffs, especially beans. One of techniques that usually used for preserving foodstuffs from insect’s attack in Indonesia is by using chemical pesticides and fumigants. The continuous use of chemicals can disrupt human health and pollute the environment. Pest control using essential oils is considered safer than chemicals and environmentally friendly. The essential oils that used in this study were A. nardus, E. globulus, and M. piperita. Nanoemulsion essential oils were made to reduce evaporation. The aim of this study is to find out the insecticidal activity of chlorpyrifos and three kinds of essential oils against Callosobruchus maculatus (F.). Research methods of this study consisted of sample preparation, fabrication of essential oils, mortality test and repellency test. The results showed that chlorpyrifos pesticides still have higher percentage of against insecticides compared to essential oils, but their use was not environmentally friendly.
Screening of biosurfactant producing bacteria from hydrocarbon contaminated soil
Authors: Kurniati T H , Rahayu S , Sukmawati D , Maharani W 
Published: December 2019

Abstract
Biosurfactants are surface-active molecule produced by microorganisms and have several advantages over the chemical surfactants. The objective of this research was to obtain biosurfactant-producing bacteria from hydrocarbon contaminated soils in Jakarta Bay and to observe their biosurfactant activity through emulsification capacity and surface tension reduction capability. Overall, 19 isolates were screened for biosurfactant production by hemolysis assay, drop collapse assay and oil spreading assay. The result showed that 13 strains gave positive results on the screening tests and were determined as biosurfactant-producing bacteria. Three strains (TKY 3, TKY 14 and TKY 19) had the best biosurfactant activity. The lowest surface tension value was achieved by two strains (TKY 19 and TKY 14) with the same value of 37,84±1,45 mN/m.
Application of biochar and compost to changes in physical and chemical properties of soil and corn yield on dry land
Authors: Putra I G L A A A , Situmeang Y P , Yuliartini M S , Udayana I G B 
Published: December 2019

Abstract
The purpose of this study was to determine the effect of biochar and compost fertilizer and their interactions on changes in the physical and chemical properties of soil and corn products on dry land. This experiment uses a randomized block design with factorial patterns. The first factor, the biochar dose consisted of 4 levels, namely: 0; 5; 10; and 15 tons ha−1. The second factor, compost dosage consisted of 2 levels: 0 tons ha−1 and 20 tons ha−1. The highest dry corn seed per ha was obtained from the treatment of 10 tons ha−1 biochar which was 9.21 tons which increased 35.56% compared to dry corn seeds per ha which were obtained from the treatment without biochar which was 6.79 tons. The treatment of compost doses of 20 tons ha−1 gave the highest value of dry corn seeds per ha, which was 8.73 tons, an increase of 16.58% compared to the lowest yield, which was 7.49 tons in the treatment without compost. The interaction between the treatment of biochar and compost dosages had no significant effect on all observed variables, except for organic C, available P, available K, and very significant CEC effect.
Phytochemical test on herbal drinks loloh cemcem at Penglipuran Village, Bali
Authors: Cahyawati P N , Lestari A , Subrata T , Dewi N W E S , Wiadnyana I G P 
Published: December 2019

Abstract
Loloh is a traditional Balinese drink that is believed to be able to overcome certain diseases. The Balinese people make loloh independently for self-consumption or trading in the small-scale home industry. The making of loloh is usually passed down from generation to generation, but until now has not been standardized. Loloh cemcem is one of the traditional drinks from The Penglipuran Village, Bangli Regency, Bali. This study aims to conduct phytochemical tests on loloh cemcem in Bali, especially from Penglipuran Village. Phytochemical tests include levels of alkaloids, steroids, terpenoids, phenolics, saponins, flavonoids, steroid, and tannins. The results of this study indicate that loloh cemcem produced in Penglipuran Village contains flavonoids, terpenoids, tannins, phenols, and alkaloids. But do not contain saponins and steroids. Loloh cemcem has the potential to be an antibacterial, antioxidant and another benefit that still needs further investigation.
Smartphones application in alkali metal flame tests
Authors: Sari S , Magfiroh E , Irwansyah F S , Farida I , Sobandi O 
Published: December 2019

Abstract
The purpose of this study is to determine alkali metal content by means of flame using smartphone application with experiment. Method stages are performed by making a standard solution and test solution first. Standard solution for determining density line equations to vector norm value. While the test solution is to determine the known concentration of NaCl from the line equations. The standard solutions of each RGB value is tested to get an equation with the value R2 must be close to or equal to 1. The analysis shows that the use values of RGB obtained from a captured image of the video is the color intensity resulting from the flame sodium metal. Level of the standard solution 1 shows result that is quite accurate with test solution levels of 0.0313 g/mL. Likewise with standard solution 2, the result is 0.0063 g/mL and standard solution 3 is 0.00032 g/mL. The value of R2 of the standard solutions must have a value close to or equal to 1. This is because the value of R2 affects the concentration results obtained. If R2 has a value that is very close to 1, an accurate result will be obtained.
The making electronic modules visualization chemical equilibrium process based on predict-oberve-explain
Authors: Sahara R , Subarkah C Z , Rahmatullah S 
Published: December 2019

Abstract
This study aims to create an e-module visualization chemical equilibrium processes based on POE (Predict-Observe-Explain) which includes sub-concepts of dynamic equilibrium, homogeneous and heterogeneous equilibrium, and factors that influence chemical equilibrium. The three main activities in this e-module are predicting, observing and explaining. The e-module was created using the Design Based Research method with ADD design (Analysis, Design, Development) which was validated by two material expert lecturers and two multimedia expert lecturers producing an overall average calculation of 0.87 while the results of the feasibility test conducted at ten students show a percentage of 98.11%. This shows that this e-module is very feasible to be used as teaching material.
Challenges and opportunities of green chemistry concepts in the Synthesis of Sodium Lignosulfonate (SLS) surfactant
Authors: Setiati R , Siregar S , Marhaendrajana T , Wahyuningrum D , Listyani A 
Published: December 2019

Abstract
Green chemical is the designing of products and processes that minimize the use and generation of hazardous substances. Synthesis of Sodium Lignosulfonate (SLS) Surfactant can be processed from bagasse, waste of sugar cane. The aim of this study was to show that sodium lignosulfonate surfactant (SLS) can be made from bagasse using the Microwave-Assisted Organic Synthesis (MAOS) with the concept of green chemistry. Bagasse processing becomes SLS with hydrolysis and sulfonation process using microwave radiation. The process is closed system, for 1 hour, with a microwave power of 300 watts at 80oC. The process is using Microwave Assisted Organic Synthesis (MAOS) which is equipped with chemical flask and condenser. Reagents are used in small concentrations, 2% NaOH and 0.1 M sodium bisulfite. The result of synthesized SLS from bagasse is brown powder. The synthesized SLS product using Green Chemical concepts has been tested with Fourier Transform Infra Red (FTIR) consisting of Alkene, Sulfonate, Carboxylic Acids and Ester. This composition is similar to the composition of the commercial SLS standard which petroleum based, using as surfactant injection in the EOR process. The Green Chemical concept has the challenge and opportunity of synthesizing Sodium Lignosulfonate Surfactant using Microwave Assisted Organic Synthesis.
Cytotoxic sesquterpenoid compound from the stembark of Aglaia simplicifolia (Meliaceae)
Authors: Kurniasih N , Supriadin A , Fajar M , Abdulah R , Harneti D , Supratman U , Taib M N A B M 
Published: December 2019

Abstract
Previous phytochemical studies from the Aglaia genus reported the presence of terpenoid compound. This research describes the isolation and structure elucidation of sesquiterpend compound from the stembark of Aglaia simplicifolia. Dried stembark of A. simplicifolia extracted with methanol and then partitioned with n-hexane, ethyl acetate, and n-butanol, respectively. The n-hexane extract then was separated and purified with chromatography techniques to obtain isolated compound. The chemical structure of isolated compound was elucidated by IR, NMR 1D, NMR 2D as well as mass spectra and by comparison with those previously reported spectra data. The compound identified as senecrassidiol. This compound showed cytotoxicity activity against HeLa cervical cancer cells with IC50 values of 2.18 µM.
Antioxidant activity of volatile compounds from Syzygium aromaticum (L.) leaves
Authors: Alawiyah A L , Senania A , Sari H , Perdana F , Musthafa I 
Published: December 2019

Abstract

Syzygium aromaticum (L.) leaf essential oil have been identified as antioxidants. This study aimed to determine the volatile compounds and antioxidant activities of Syzygium aromaticum (L.) leaf essential oil. Syzygium aromaticum (L.) leaves were extracted by steam distillation. The identification of volatile compounds was done by Gas Chromatography Mass Spectroscopy (GC-MS). DPPH test was used to evaluate the sample’s antioxidant activity. The results provide information that the extract have 15 of volatile compounds from Syzygium aromaticum (L.) leaf essential oil. Moreover, DPPH test has identified a very strong antioxidant by IC50 values was 8.224 µg/mL.
Titration pre-lab demonstration videos in basic chemistry laboratory activity: Design and development
Authors: Fitriani E , Paristiowati M , Mukarromatunnisa B 
Published: December 2019

Abstract
There are difficulties for first-year chemistry students to adapt to chemistry laboratory activities due to their lack of experience in their schools. As a result, it affects their confidence and also their safety awareness in the laboratory. One of the very basic required skills in a chemistry laboratory is undertaking titration. This multi-year study aims to design and develop chemistry pre-laboratory demonstration videos to make students familiar with the required laboratory skills before they start laboratory activities. The data were collected by paper-based and online questionnaires, observation, and inverview. According to the evaluation by users and experts, the usability and feasibility of the videos were categorized as very high. Moreover, corrections and suggestions were implemented to improve the quality of the videos.