bluuebunny/crossref_metadata_2025_split huggingface dataset:
Design and development of measurement of measuring light resistance using Light Dependent Resistance (LDR) sensors
Authors: Setya W , Ramadhana A , Ramadhana A , Restu Putri H , Santoso A , Malik A , Chusni M M 
Published: December 2019

Abstract
Light Dependent Resistance (LDR) is one type of resistor whose resistance value is affected by the intensity of light received by it. This study aims to measure the amount of resistance in each color of light measured in the LDR. The research method is done by making a measurement device in which a light source parallel to the LDR is placed, where the color layer is inserted which will change the white light from the lamp to the color light according to the color layer used. The variation in distance (x) between the lamp and LDR causes greater resistance. The results of this study indicate that 1) the distance of the light source is inversely proportional to the intensity of light, 2) The distance of the light source is directly proportional to the magnitude of resistance, 3) The intensity of light is inversely proportional to resistance, and 4) the dominant large resistance value is in the dominant blue light the value of large light intensity is in the color of yellow light.
Analysis of sound frequency exposure at growing phase of Chrysanthemum Sp. (Case study: Exposure by Quran recitation)
Authors: Chaidir L , Kamelia L , Rahman A 
Published: December 2019

Abstract
Sound wave technology or Sonic Bloom technology has long been applied to plants. Sound waves affected the plants at different frequencies, sound pressure levels, presentation periods, and distances from sound sources. The aim of this research is to determine the effect of sound technology exposure on certain frequencies on the beginning of shoot growth, plantlet height, leaf number, and stomata opening width. The experiment was conducted by comparing chrysanthemum plants exposed to Quran recitation (Surah Al-Fatihah) at an average frequency of 1237.8 Hz for 2 hours for 8 Weeks After Culture (WAC). The results showed that Quran recitation and media interactions occurred in plantlets height after 4 WAC and leaf number after 8 WAC. The exposure of Quran recitation had affected on plantlet height after 2 WAC. The treatment influenced the number of leaves after 4 WAC, and the number of roots after 6 WAC. In testing the opening of the stomata, the leaves that given al-Fatihah recitation treatment, having a stomata opening wider than the leaves that were not treated (control). This study is the beginning of research to find the right frequency to stimulate growth in plants.
Study of pH influences on the performance of Na-loaded NbOPO4 solid acid catalyst for biofuel production
Authors: Sy Y , Nurhazanah N , Maulana A , Mahidin M , Husin H 
Published: December 2019

Abstract
This study reports on the development, preparation, and performance test of NbOPO4 solid acid catalyst for biofuel production from vegetable oil. NbOPO4 catalyst was synthesized by sol-gel method using NbCl5, H2SO4, and citric acid as the precursor solutions and chelating agent, respectively. Dependent variables in the study were calcination time of 5 h; NbOPO4 loading of 2%; transesterification time of 3 h; reaction temperature at 65-70°C and oil mass of 30 g. Whereas, the catalyst pH of 2, 4, 6, 9, and Na impregnation ratio of 20-50% were set as independent variables. The catalyst morphology was analysed by Scanning Electron Microscopy, catalyst elements was detected by Electron Dispersive X-Ray and X-Ray Diffractometer was used to characterize the crystallinity degree of the catalyst. The performance of the catalyst was evaluated from a transesterification reaction for biofuel production. The highest biofuel yield of 98,5% was obtained in the reaction using catalyst with a pH of 4 and Na impregnation ratio of 30%. The density obtained was 0,860 gr/cm3 confirming that the produced biofuel complies with the SNI. It can be concluded that Na-loaded NbOPO4 can be a promising alternative catalyst in biofuel production.
Effect of addition sodium lignosulfonate additive in g class cement on thickening time and compressive strength
Authors: Rosyidan C , Samura L , Maulani M 
Published: December 2019

AbstractCementing process was not good can be caused by the poor planning of cement slurry carried out in the laboratory. Poor cementing certainly cannot meet the expectations and goals of the cementing process. The purpose of this study was to select the right and optimal cement composition by testing sodium lignosulfonate retarder additives for thickening time and compressive strength. The methodology used in this study was laboratory testing using class G cement. The addition of sodium lignosulfonate additive in this class G cement was obtained the highest thickening time value at a concentration of 1.5% temperature 150 ° F for 24 hours test result.
Determination of CO2 volume injection effect to reservoir fluid characteristic in miscible CO2 displacement
Authors: Hartono K , Aditya Y , Sudibjo R , Fathaddin M T , Pratiwi R , Fadliah F 
Published: December 2019

Abstract
Carbon dioxide (CO2) miscible flooding is one of the Enhanced Oil Recovery (EOR) methods that has been recognized as a promising method to improve of oil recovery before abandonment. In addition, many issues related to global warming or greenhouse effect due to CO2. By using CO2 as either miscible or immiscible flooding to enhance oil recovery injected into reservoir, it may help reduce environmental problems. Carbon dioxide (CO2) is able to improve of oil recovery effectively by important key parameter: minimum miscibility pressure (MMP), viscosity, and density. This paper aims to determine the effect of CO2 volume injection to reservoir fluid characteristic in order to CO2 miscible flooding for displacing the oil production. This research was carried out by some series of laboratory experiment that involve PVT test, slim tube test, and swelling test. The result from laboratory experiments were used to observe the use of CO2 and its effect on reservoir fluid characteristics such as viscosity, solubility, and swelling factor. MMP obtained from slim tube test is 2805 Psi. Based on the results, all trend of parameters: viscosity, solubility, and swelling factor showed the positive impact of CO2 have on liquid recovery.
Reinforcement of chitosan film using cellulose isolated from grass (imperata cylindrica)
Authors: Az-Zahra N , Rahmi R , Lubis S 
Published: December 2019

AbstractCellulose from grass (imperata cylindrica) had been used as reinforcement in chitosan film preparation. Cellulose was obtained from grass through hydrolysis process. Hydrolysis was conducted with different concentration of sulfuric acid at room temperature for 2 h. The results show that the highest crystallinity of cellulose was obtained at sulfuric acid concentration of 40% (v/v) on hydrolysis process. The isolated cellulose with the highest crystallinity was used as reinforcement on chitosan film preparation. Mechanical test shows addition of isolated cellulose into chitosan film improved the tensile strength. The FTIR analysis confirmed the interaction between components in the film.
The making of electronic modules on alternative fuels material based on green chemistry
Authors: Afifah A , Subarkah C , Aisyah R 
Published: December 2019

Abstract
This research was conducted to produce teaching materials in the form of e-modules on alternative fuels based on green chemistry fuel material. The presentation of material and visualization that used in this e-module based on green chemistry includes the losses caused by the use of fuel oil and the solutions offered to overcome them by the presence of alternative fuels based on green chemistry. This research uses the Design Based Research method with the ADDIE model. The e-module is tested for its feasibility. The results of the feasibility test show 94-100% of the respondents agreed to all the criteria in the e-module. These results indicate that the green chemistry-based alternative fuel e-module that has been made is feasible to use. This research is useful to increase student awareness about the importance of protecting environment through chemistry learning process.
Derivative Uv-Spectroscopic determination of theophylline, salbutamol sulfate and glycerylguaicolate in syrup mixture
Authors: Suryana S , Nurjanah N S , Permana B , Prasetiawati R , Lubis N 
Published: December 2019

Abstract
This study aimed to determine theophylline, salbutamol sulfate and glycerylguaiacolate using ultraviolet spectrophotometry derivative. Research conducted in syrup was analyzed using zero crossing wavelength method. NaOH 0,1 N was selected as the solvent. Zero crossing wavelength of theophylline was 275 nm on the first derivative, salbutamol sulfate was 262 nm on the second derivative and glycerylguaiacolate was 243 nm on the third derivative. Results showed that the recovery of theophylline and glycerylguaiacolate were between 112,913%-118,353% and 116,129%-117,655%, respectively, while the relative standard deviation was between 1,090%-1,903% for theophylline and 1,013%-1,922% for glycerylguaiacolate. Limits of detection of theophylline and glycerylguaiacolate were 1,626 ppm and 6,375 ppm, respectively while limits of quantification were 4,927 ppm and 19,319 ppm. This results Thus, it was concluded that this method could be applied to determine theophylline and glycerylguaiacolate in syrup mixture.
Analysis of flavonoid in extract of Rose Guava (Syzigium jambos (L.) alston) leaves using infrared spectroscopy and chemometrics
Authors: Suryana S , Junaedi E C , Choerunisa Y , Prasetiawati R , Lubis N 
Published: December 2019

Abstract
This present study was carry out to determine total flavonoid contents of ethanol extract of Rose guava leaves using combination of FTIR and Chemometrics. Flavonoid was extracted from Rose Guava leaves by maceration. IR spectra were correlated with flavonoid content using chemometrics. The chemometric method used for calibration analysis was partial Last Square Regression (PLSR). Partial least squares regression (PLSR) was used to build a prediction model based on the relationship between concentration of total flavonoids obtained from the reference method (AlCl3) and FTIR spectrum. The results of the combination of FTIR and chemometrics on the prediction of total flavonoid levels has resulted in a good predictive model with calibration values of R2 0.9999, RMSEC 0.0000637 and the results of PRESS value of 0.19225, R2 0.978 and RMSECV 0.041. From these results, combination of FTIR spectrum and PLSR can be used for the prediction of total flavonoids content of Rose guava leaves.
The making augmented reality technology-based learning media in molecular hybridization concept
Authors: Asyiah E N , Irwansyah F S , Farida I 
Published: December 2019

Abstract
This study aims to describe the appearance of AR technology-based learning media on the concept of molecular hybridization. Design based research has produced products in the form of AR technology-based learning media on the concept of molecular hybridization. Research shows completing media creation, design development and application creation and analyzing the results of limited trials. This study shows the appearance of learning media AR has several characteristics namely attractive colors and appearance, and interactive and the making of AR technology-based learning media has the potential to be applied to chemical learning in accordance with the concept of molecular hybridization.
Antioxidant potentials of virgin olive oil and virgin coconut oil and its cream formulation
Authors: Djalil A D , Setyawan H , Gumelar M I , Nurulita N A , Budiman A 
Published: December 2019

Abstract
Exposure the ultraviolet (UV) radiation results in a photo-oxidative reaction that reduces the antioxidant defence system and increases the formation of reactive oxygen species (ROS) on the skin. Antioxidant creams protect the skin from adverse effects of UV which cause the initial signs of aging. Several creams containing 0.02 (F1); 0.2 (F2); and 2% of virgin oil were prepared. Antioxidant activities of virgin olive oil (VOO), virgin coconut oil (VCO), and the creams were evaluated by DPPH radical scavenging assay. The results showed that the oils and VOO cream formulations have antioxidant activities. Based on antioxidant activity study, VOO was selected as an active compound for the development of the antioxidant cream formulation. The EC50 values of VOO, F1, F2, and F3 of VOO were 31.7±0.1; 176.3±5.9; 111.9±4.7; 90.4±5.5 µg/mL, respectively. Furthermore, The EC50 value of VCO was 44.7±2.0 µg/mL. The formulation of antioxidant cream containing VOO meets the requirement of physical properties and stability, except when evaluated by cycling test.
Chemistry students’ soft skills development through the integration of Think Pair Square (TPSq) using a socio critical and problem oriented approach in acid-based learning
Authors: Hadinugrahaningsih T , Amalia R , Fitriani E , Rahmawati Y 
Published: December 2019

Abstract
The aim of this research was to develop the chemistry students’ soft skills through acid-based learning by integrating Think Pair Square (TPSq) using a socio critical and problem-oriented approach. The study involved 36, year 11, secondary school students. A qualitative research methodology using interviews, observations, a VLES questionnaire, and a reflective journal was employed to understand the process and to engage the participants. The issues of 1000mg vitamin C, “kangen water”, and infused water in relation to acid-base concept water was used to encourage students’ critical thinking in solving the problems. The results showed that students were engaged and motivated in meaningful chemistry learning experiences, while the teacher was challenged in the role of facilitator. The soft skills of collaboration and communication, and critical and creative thinking were stimulated during the process. The students learned to reflect on their own values during debate whilst solving the problems. Learning implications observed during the process showed that students’ soft skills developed during the learning process.
Anti-elastase activity of methanolic and ethyl acetate extract from Garcinia latissima Miq.
Authors: Ambarwati N S S , Elya B , Desmiaty Y 
Published: December 2019

Abstract
Elastase is a proteinase enzyme that can reduce elastin by dividing specific peptide bonds. Therefore, the inhibition of elastase activity in the dermis layer can be used to maintain skin elasticity. Materials that can inhibit elastase activity can be a cosmetic ingredient in dealing with skin aging. Increased desire to maintain healthy skin without chemicals, encourages the use of materials from natural sources such as plants from Indonesia, a country that has high biodiversity, including Garcinia latissima Miq. from the Clusiaceae family. The purpose of this study was to explore and sought an explanation as to why G. latissima Miq. inhibits elastase enzyme. Plant extraction was carried out using maceration successively methods. The inhibition activity of elastase enzyme was carried out by measuring the kinetic enzyme N-succ-(Ala)-3-Nitroanilide conversion to p-nitroaniline (substrate) spectrophotometry at 405 nm and using porcine pancreatic elastase (PPE) as an enzyme. The results showed that the G. latissima Miq. methanol extract and ethyl acetate extract were active as elastase enzyme inhibitors. G. latissima Miq. extract can maintain skin elasticity.
Difference inhibitory power between extract of Guava Leaves and Bay Leaves against Escherichia coli Bacterial growth
Authors: Witari N P D , Nahak T M , Semadha W 
Published: December 2019

AbstractEscherichia coli is a Gram-negative bacteria that has a natural habitat in the human digestive tract. This bacteria is a normal flora but have a potency to be pathogenic. Escherichia coli is the most common cause of diarrhea. Guava leaves and bay leaves contain essential oils, tannins, flavonoids, and saponins which have antimicrobial effects. The purpose of this study was to determine the difference in the effectiveness of inhibition between ethanol extract of guava leaves and bay leaves on the growth of Escherichia coli bacteria. This research was an experimental laboratory study. The inhibitory test was carried out by measuring the clear zone around the paper disc using calipers. The results of data analysis using one way ANOVA showed that there were significant differences between groups of extracts with F output = 49.83 and p = 0.00 (p≤ 0,05). Guava leaf extract concentration of 10%, 30% was significantly different from bay leaf extract concentration of 10%, 20%, 30%, with a p-value ≤ 0.05. The conclusion of this study is Ethanol extract of guava leaves has a higher inhibitory ability than the ethanol extract of bay leaves.
Setting of cash pruning time and giving rabbit urine to growth and results of plant melon (Cucumis melo L.)
Authors: Sunadra I K , Wirajaya A A N M , Kartini L , Yuliartini M S 
Published: December 2019

Abstract
Melon is an annual plant that has high economic value with bright prospects to be developed. The low production of melons needs to be improved on cultivation techniques. The purpose of this study was to get one of the right time to trim the shoots and giving the urine more often given will be able to give effect to the growth and yield of melon plants both the best quality and quantity as well as the increasing income of melon farmers. Factorial experiments (2 factors) with a randomized block design (RBD) were used in this study. The interaction between setting the shoot pruning time (P) and giving rabbit (U) urine to the growth and yield of melon plants on all influential variables was not significant. The highest weight obtained fruit weight per plant due to setting the shoot pruning time gave at P1 of 1555.21 g or 10.12%, it was higher compared to P3 which was 1412.34 g. Fruit weight per plant on U1 urine administration with the interval of giving once every 3 days showed the highest value of 1568.88 g or 14.67%, it was higher compared to U0 which was of 1368.17 g.
Preparation and characterization of Seaweed based Bioplastic Blended with Polysaccharides derived from various seeds of Avocado, Jackfruit and Durian
Authors: Yusmaniar Y , Syafei D I , Arum M , Handoko E , Kurniawan C , Asali M R 
Published: December 2019

Abstract
Anticipating the global trends of biodegradable plastic and its application to packaging industries, this study was conducted to prepare a seaweed (Eucheuma cottonii) based biodegradable plastic blended with polysaccharides derived from various tropical fruit seeds which are abundantly available in Indonesia such as avocado, jack fruits and durian. The objective is to prepare an environmentally friendly and edible bioplastic. The various polysaccharides were obtained through extraction and the bioplastic blends were heated at 80°C for 30 minutes. The characterization conducted include mechanical properties, thermal and biodegradability analysis, spectral and surface analysis through Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscope (SEM) respectively.
Comparison of gas initial in place calculation using MBAL and Artificial Intelligence methods
Authors: Nugraha F P , Setiati R , Fattahanisa A 
Published: December 2019

Abstract
Oil and gas industry are an industry with a high cost and high risk, artificial intelligence will help the work of humans to minimize the risk of accidents, reduce processing time and improve corporate profits. So, the work becomes more efficient. The aims of the study give information that the artificial intelligence help the work to evaluate the initial gas in place on reservoir and comparison the results between software and manual Material Balance (MBAL). Additional research is needed to know the type of reservoir and drive mechanism. The method used is the research on reservoir RGN, the data used are based on real data in field. This research uses artificial intelligence MBAL software and calculation with manual MBAL. Based on the analysis, the result of reservoir type dry gas reservoir with drive mechanism is depletion drive. Calculation initial gas in place using artificial intelligence MBAL software, get the initial gas in place result of 50661,3MMscf. And calculation using manual MBAL, get the initial gas in place result of 50063,59MMscf. There is a difference in the results of the initial gas content in place of 597.4 MMscf. Based on the analysis, there are differences in the results between using artificial intelligence and manual MBAL.
Influence of soaking time on tensile strength of coconut fiber
Authors: Arsyad M , Soenoko R , Arman A , Wahyuni N 
Published: December 2019

AbstractThe objectives of research are to determine the effect of long soaking of coconut fiber in alkali solution to the tensile strength of coconut fiber. The testing stages include preparation, soaking, drying, testing, and analysis. The materials used consist of coconut fiber, alkali solution, aquades, tensile test equipment, and furnace. Coconut fiber is soaked in an alkali solution with a concentration of 20% for 1, 5, 7, 9, and 11 hours. Then, the coconut fiber was rinsed with aquades before being dried in a furnace at 90°C for 5 hours. Furthermore, tests of mechanical properties include a single fiber tensile of coconut fiber with ASTM 3379-02 standart. Based on the results and discussion, it can be concluded that (a) the alkali treatment decreases the amount of hemicellulose and cellulose in coconut fiber, (b) the lowest hemicellulose and cellulose content was obtained at 7-hour immersion i.e. 8.85% and 18.40%, (c) the maximum tensile strength obtained at 7 hours of soaking is 223.907 N/mm2.
Effect of trivalent manganese substitution in α-Al2O3crystal on the absorption spectra based on first-principles calculations
Authors: Novita M , Nuvitalia D , Cholifah N , Ogasawara K 
Published: December 2019

AbstractThe absorption spectra of α-Al2O3: Mn3+at low-spin (LS) state have been estimated based on first-principles calculations without referring to any experimental parameter. The effect of lattice relaxation due to the Mn3+substitution was considered under several computational procedures such as the Shannon’s crystal radii method and the geometry optimization using Cambridge Serial Total Energy Package (CASTEP) code. Two different sizes of model clusters consisting of 7 and 63 atoms were compared. Next, the molecular orbitals (MO) were estimated using the one-electron calculations discrete variational-Xα (DV-Xα) method while the absorption spectra were estimated using the many-electron calculations discrete variational multi-electron (DVME) method. The results show that the lattice-relaxation ratio is about ca. 104.05-106.43% depending on the computational conditions. Due to the Mn-O bond-length elongation, the crystal field splitting (10Dq) decreased ca. 0.24-0.41 eV. Thus, the peak position originating from3T1→3E transition energy shifted toward the lower energy ca. 0.10-0.26 eV. Both of the larger-cluster size and the lattice-relaxation effect decrease the peak energies.