bluuebunny/crossref_metadata_2025 huggingface dataset:
Direct and indirect measurement techniques of cavitation intensity: a brief review
Authors: Triawan F , Budiman B A , Nurprasetio I P , Sunnardianto G K
Published: December 2019

Cavitation has been one of the critical issues in turbomachinery operation which often causes the reduction of service life of the components. In order to predict the service life, cavitation intensity (CI) needs to be measured accurately. In this paper, several notable developments of techniques to measure CI are reviewed briefly. Those techniques can be classified into two groups, i.e. direct and indirect measurements. For the indirect technique, a method which estimates the impact load of bubble collapse by inverse analysis is particularly elaborated. For the direct technique, a method which utilizes painting technique to quantify the actual CI is specifically presented. The advantages and disadvantages of both direct and indirect techniques are also discussed.
Analysis of fire rate on paper coated with the silica gel from rice husk ash
Authors: Sutrisno H H , Wirawan R , Febriani A , Ambarwati D
Published: December 2019

Silica element can be used as one of additional elements in a material. It is good to improve the thermal properties so it can stabilize the heat resistance of a material. The silica gel resulted from the extraction process of rice husk ash can also do the stabilization of heat resistance. This element is known to be able to reduce the fire rate in a material. In this research, the fire rate on a paper is analyzed from the result of paper coating by using the silica resulted from the extraction of rice husk ash. It is done by using the flammability test device. The silica gel used to coat the paper is obtained from variety of time during the extraction process, so it will give a difference toward the fire rate on the paper. From the research result, the paper coated by the silica gel sourced from the extraction of rice husk ash with the shortest amount of heating time has the lowest fire rate compared to other samples. It means that the percentage of silica gel obtained from the extraction of rice hush ask with various time variety is in line with the reduction of fire rate.
The influence of engineering students numerical reasoning on the academic achievement of Computer Numerical Control (CNC) course
Authors: Dudung A , Nurhidayat D , Yuliatmojo P
Published: December 2019

The research aimed to examine the relationship between numerical reasoning abilities and academic achievement in CNC (Computer Numerical Control) course and the contribution of numerical reasoning of CNC course. This study employed a survey method with correlational causal relationships. The stratified random sampling proportional technique is employed with 30 engineering students. The results of the study show the significant relationship between numerical reasoning and academic achievement of CNC course with r count = 0.76. The two coefficients are terminated by independent variables (predictors of X) for changes in the dependent variable (Y criterion) of R square = 57.8%. The results show that there is a positive relationship between the two variables. Therefore, the learning experiences should provide the opportunities for students to develop their numerical reasoning.
How vocational high-school students understand geothermal energy
Authors: Wahyudi W , Pambudi N A , Biddinika M K , Basori B , Rudiyanto B
Published: December 2019

Indonesia has the highest potential of geothermal energy in the world with 28,5 GW. However, the utilization ratio is low with around 6% only. This situation occur since there are several geothermal energy targets failed to be achieved. The development of geothermal energy has several problems and one of them is rejection in the community when geothermal development begins. To overcome this situation, an increase in community understanding of this technology usage needs to be conducted. Therefore, the objective of this study is to discover public understanding by exploring the knowledge of vocational high school students about geothermal energy. This is conducted because they are young people who are part of the community. Their knowledge plays an important role in selecting energy sources for the country in the future. This study uses a triangulation strategy model that combines quantitative and qualitative methods. Respondents were students in Indonesia with a case study in Karanganyar Regency, Central of Java. Knowledge is measured by an indicator of the level of understanding of geothermal technology.
The influence of acid and base solutions on the quenching process against the hardness of ST37 steel
Authors: Akbar A , Firdaus R , Mulyadi M
Published: December 2019

Previous research stated that salt water cooling media has higher hardness value after going through the heat treatment process compared to freshwater cooling media. From this explanation, a study was conducted on the effect of using acid and alkaline solutions in the quenching process against the hardness of ST37 steel. This study uses vinegar water cooling media and soapy water. In this study several steps were carried out, namely: hardening on ST37 steel with a heating temperature of 700ºC with a holding time of 15 minutes, direct quenching with acidic cooling media (vinegar: 2.4 pH) and alkaline solution (soap water: 9.3 pH ) with a 15 minute holding time. After the heat treatment process and direct quenching on ST37 steel, Rockwell hardness was tested. From the test results, the use of acid and base solution cooling media in the quenching process has an effect on the hardness of ST37 steel, the best hardness value is an alkaline solution compared to an acid solution, alkaline solution has a hard value of 66.73 HRC, while acid solution has a hardness value of 64.31 HRC. The results of this study will be one of the references for further research, especially the use of weak acid-base solutions as a cooling medium.
Microwave absorbing characteristics in multilayer absorbers based on barium ferrite and teflon
Authors: Handoko E , Susila A B , Sugihartono I , Marpaung M A , Jalil Z , Alaydrus M
Published: December 2019

In order to investigate a new microwave absorbing characteristics of multilayer absorbers. Barium ferrite BaFe12O19 was synthesized by a standard ceramic method. Teflon was obtained from the china product and is available in the market. Multilayer absorbers based on 2 mm of barium ferrite layer thickness and 0.5 mm of teflon layer thickness with 2, 4, 6 and 10 layers were characterized by using vector network analyzer (VNA) Rohde-Schwarz ZVA 67 for 7.5 – 11.5 GHz frequencies. Reflection loss (RL) of multilayer absorbers were calculated and simulated using the transmit line theory. The microwave absorption abilities were enhanced for multilayer structure due to the combination of barium ferrite and teflon layers. The optimal absorption ability was achieved with − 20 dB (i.e. 99.9 % absorption) of reflection loss.
Energies of the static solitary wave solutions of the one-dimensional Gross-Pitaevskii equation
Authors: Prayitno T B , Budi E , Fahdiran R
Published: December 2019

We calculated the energies of the static solitary wave solutions of the one-dimensional Gross-Pitaevskii equation with the time-dependent parabolic trap, the time-dependent scattering wave length of s-wave, and the time-dependent external potential describing a gain or loss term. Some written solutions of the equation were used, two of which are based on the experimental results. The solutions satisfy the condition of solitary wave solution since they are localized over the space. By this argument, the energies were obtained by integrating the Hamiltonian density over the space formulated in the classical field theory. To do that, we constructed the appropriate Lagrangian density representing the equation by initially writing the ansatz Lagrangian density and then substituting into the Euler-Lagrange equation. We found that two of the solutions have the same energies and the other one should mathematically have the pure imaginary function describing the gain-loss term to achieve the real energy.
Ideal gas model of Bose-Einstein condensates confined in the parabolic trap
Authors: Prayitno T B , Budi E , Fahdiran R
Published: December 2019

By using the one-dimensional canonical partition function, we modelled an ideal gas-like form of a set of Bose-Einstein condensates confined by a three-dimensional anisotropic parabolic trap. The model itself was constructed by taking the eigenenergies of the one-dimensional Gross-Pitaevskii equation in the longitudinal direction and enabling the harmonic volume as the inverse cube of average geometric trapping frequency to substitute the real volume. In this paper, we showed that the condensates form an ideal gas represented by its equation of state and have similar mature to Einstein’s solid-like model with the corrections in both the low and high temperatures in the internal energy formulations.
PASSING for experiment tool in elasticity and hooke’s law concept on springs arranged in series and parallel
Authors: Suhendi H Y , Nurhasanah S , Yuningsih E K , Mulhayatiah D , Malik A
Published: December 2019

This study aims to analyze the feasibility of learning media PASSING (String Series Parallel) for concept elasticity and Hooke’s law. The method used in this study is ADDIE developed by Robert Marie Branch. The stages are Analysis, Design, Development, Implementation, and Evaluation. The steps of this study are: 1) Curriculum analysis, analysis of the results of interviews and questionnaires of students, and analysis of literature studies, 2) Designing learning media PASSING, 3) Realizing PASSING practicum tools 4) Performing expert validation tests 5) Product revisions. The results of the study obtained a tool validation value of 90.47% with a feasible category. This study concluded that PASSING is feasible to be used as a learning media in the concept of elasticity and Hooke’s law.
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

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

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

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

Cementing 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

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

Cellulose 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

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

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

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

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

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

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

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

Escherichia 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

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

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

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

The 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

The 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.
Effect of sintering temperature on structure and morphology of Ca0.95La0.02Bi0.03MnO3 perovskite manganite prepared by sol-gel method
Authors: Faruq U , Kurniawan B
Published: December 2019

The effect of sintering temperature on the structure and morphology of Ca0.95La0.02Bi0.03MnO3 was investigated by X-ray diffraction and Scanning Electron Microscope. The sample was prepared by sol gel method. Their homogeneity was confirmed using X-ray diffraction. Rietveld refinement of X-Ray diffraction results showed that the sample sintered at 1100 °C for 12 h are single phase and have an orthorhombic structure with Pnma space group. While, the samples were sintered at 900 °C and 1000 °C did not show a single phase due to another peak is found. For the lattice parameter, crystal volume increases with increasing sintering temperature. The largest crystal volume was reached at sintering temperature 1100 °C which is equal to 208.7319 Å. For the angle of the Mn-O-Mn bond, the sample was sintered at 1100 °C has the largest value obtained 157.6695° while at 1000 °C is 157.1440° and 900 °C is 157.3655°. For the average Mn-O bond length shows relatively the same value for all sintering temperature. The sample was sintered at 1100 °C had the largest grain size. Sintering temperature does not change the crystal structure of Ca0.95La0.02Bi0.03MnO3 samples
Synthesis of zeolite NaX using elephant grass (pennisetum purpureum) as a silica source and its characterization
Authors: Setiadji S , Sundari C D D , Aprilia V , Sumiyanto E , Novianti I , Ivansyah A L
Published: December 2019

Zeolite NaX is a synthetic zeolite with faujasite framework that has large pores, which it is largely used as adsorbents. Zeolite NaX was synthesized using silica (SiO2) which was extracted from elephant grass (Pennisetum purpureum). The silica was isolated from elephant grass using its ash with conventional ignition method, with NaOH as solvent. The extracted silica purity is 86.33%. Zeolite NaX was synthesized with 3.5 Na2O : Al2O3 : 2.9 SiO2 : 150 H2O as molar ratio in hydrothermal condition at 90 °C for 15 hours. Synthesized zeolite was then characterized using FTIR to confirm the formation of zeolite based on chemical bonding that appears on the spectrum, XRD to confirm the framework structure of the formed zeolite, and SEM to obtain its morphology. Based on those analysis, it is known that the result of synthesis process is zeolite with NaX crystal structure and octahedral morphology with crystal sizes range 1-5 µm.
Characteristic fillet of aloe vera gel as edible coating
Authors: Suriati L , Utama I M S
Published: December 2019

This research aims to know the influence of storage temperatures against characteristics fillet of Aloe Vera that is potential as an edible coating. This study used a randomized complete design. Colour fillet Aloe Vera clear white initially when stored at room temperature turns pink on day 2. While stored at cool temperatures the color change on day 4. The gel is stored at cool temperatures have pH and moisture content are relatively stable, decreased severity is also lower compared to the store at room temperature. Aloe gel fillet show change of characteristic beginning at day 4 when gel is stored at ambient temperatures. A decrease in activity is also evident when the fillet stored refrigerated, even though the rate of activity loss is greatly reduced. The losses of activity appear to be result of enzymatic activity after the leaf is removed from the plant. The characteristic of fillet Aloe Vera gel that storage at cool temperatures better than storage at room temperature, and decreased with the longer storage It can be seen from color characteristics change, lower weight loss, decreased water content and pH of relatively more stable.
Laboratory study influence pore volume in compressive strength foam cement
Authors: Santoso A , Setiati R , Hamid A
Published: December 2019

Pore volume of foam cement is a main factor affected compressive strength in the addition axial load design. Foam agent material used in this research is Sika-aer as a replace the nitrogen gasses. This research study used mix composition cement 1 : silica sand 0.25 : water 0.5and foam agent 0.03% - 0.15% BWOC. The purpose of this study is providing alternative cementing product beside lightweight cement in oil and gas industry with foam cement to mitigate loss circulations. Compressive strength testing was carried out with different time periods and pore volume testing were carried out on each addition/change in foam agent concentrations every cement slurry mixture. Characteristics of bubbles on cement slurry is one of many factors that influences compressive strength parameters. Compressive strength foam cement depends on size, diameters and relationship between bubbles on the cement slurry. This laboratory study produced compressive strength values between 1078 psia – 3745 psia and pore volume values between 15 cc – 17 cc in 5 samples core foam cement with different foam agent concentrations Sika-aer.
Synergistic effect of a cobalt dopant and Au nanoparticles on the photocatalytic activity of ZnO nanorods
Authors: Putri A E , Fauzia V , Roza L
Published: December 2019

The photocatalytic performance of zinc oxide nanorods (ZnO NRs) still needs improvement. In this regard, the addition of noble-metal nanoparticles (NPs) and doping with transition metals can be employed. In this study, nanocomposites of ZnO NR/Au and Co-doped ZnO NR/Au NPs were synthesized by ultrasonic spray pyrolysis and hydrothermal method and subsequently used as photocatalysts for the degradation of methylene blue. Results revealed that pure ZnO NRs exhibit a degradation rate of only 28.8%, while ZnO NR/Au NPs exhibit a degradation rate of 37.3%, and Co-doped ZnO NR/Au NPs exhibit the highest degradation rate of up to 46.5%. Based on these results, the presence of Au on the ZnO NR surface can enhance the photocatalytic activity due to its key role as an electron sink, which reduces the recombination rate of electrons and holes, while the incorporation of Co into ZnO NRs can also enhance the number of crystal defects, which can widen the visible-light absorption spectrum.
Novelty Luther-Sutopo method for game development
Authors: Satwika I P , Untoro W , Ardyanti A A A P , Sujarwo W
Published: December 2019

This research proposed a new Luther-Sutopo method to create multimedia product. The old Luther-Sutopo method was successfully used to create a multimedia product like a movie, video or interactive multimedia application and game. But there was missing maintenance step as one of important step to successfully develop a game. On the other side, Luther-Sutopo method only suitable for short term game development without considering the sustainability of multimedia development. In this paper, we aimed to create a framework that modify basic Luther-Sutopo concept. The new framework has been tested to create Bedugul Forest game. The study found that the framework successfully applied to create the game and the development process more suitable for game development with limited resources.
Enhancement three-pass protocol security with combination caesar cipher and vigenere cipher
Authors: Rahim R , Rosid M A , Fitrani A S , GS A Daengs , Ginantra N L W S R
Published: December 2019

Key-based security is still the most widely used form of security today with a key distribution process between senders and receivers that is commonly perform and also it is a classic problem in cryptography where key must be share to other parties (sender or receiver) and its maybe known when third parties do sniffing process or man in the middle attack. Three-Pass Protocol is one solution that can be used to overcome the problem of key distribution, because the sender and receiver can encrypt and decrypt without need to exchange keys. Security in Three-Pass Protocol uses XOR logic so that the resulting ciphertext will be very easy to decrypt by those who are not responsible, to improve data security in the Three-Pass Protocol process which is use Caesar Cipher and Vigenere Cipher algorithms in the encryption and decryption process in the Pass Protocol scheme, and ciphertext encryption results are quite difficult to read and require a long time to decrypt them.
“Hijaiyah” interactive learning for pre-school students
Authors: Pradibta H , Nurhasan U , Pramesti T D , Suryadi S B
Published: December 2019

Limited time allocation for Islamic education in primary schools is an obstacle for the students to understand the lesson. The core of Islamic education is to understand reading and to write letters Hijaiyah. The concept of traditional learning patterns and lack of time made the level of understanding of students is low. Hence, learning media are needed to attract student’s attention. Especially in children of the present era who are challenged with various types of technology, including mobile phones, televisions, and computers. The role of IT-based media can be a solution in current learning. In the learning process, especially for children, is learning that gives birth to a pleasant atmosphere. Images and sounds that appear will make children not get bored quickly so that they can stimulate learning in children. In learning that involves the media in the process of learning certainly must consider aspects of early childhood development. Augmented Reality can be utilized in various fields, including education. In learning, there are Quantum Learning theories, which explain visual, audio, and kinesthetic (VAK) methods. From here, Augmented Reality and Quantum Learning theories are interconnected. In this application, there will be Hijaiyah letters that are simulated in the form of AR with a sound and how to pronounce it. This application is to help the learning process of Hijaiyah letters, only by scanning the Hijaiyah letters from the Android camera.
Smart tourist guide application for the introduction of Malang city tourism potential using hybrid technology
Authors: Nurhasan U , Pradibta H , Suryadi S B , Alfinda A
Published: December 2019

Tourism in Malang City with Strategic City Branding (Beautiful Malang) is one sector that contributes significantly to efforts to increase regional income. The variety of types of tourism that exist, it needs to be supported by the existence of a good information dissemination system. The existence of this system makes it easy for women to get access to regional tourism information. In this study, two technologies were used, namely geographic information systems and augmented reality. The use of GIS technology aims to provide information that is geographically related to a tourism object. While Augmented reality is used to bring up 3D objects along with information relating to the tourism object. In its application, this application was successfully used with 90% of respondents expressed satisfaction with the performance of the application. The rest complained about the delay when scanning the tourism object markers. The use of this hybrid technology is expected to be able to provide tourism information with more attractive packaging as well as an educational media for tourism promotion. For further development, it is necessary to apply an efficient data parsing concept so that there is no delay when there is a data request.
Classification of stamps and handmade batik based on pattern recognition
Authors: Firdaus M D , Nugroho H
Published: December 2019

Batik is a traditional cloth made by painting motifs with Indonesian culture nuance on plain cloth. It has always been used by the people, from their birth until marriage, even someone who died using batik cloth as a cover. Batik cloth made with philosophy and symbolic meaning. Every region in Indonesia has a characteristic according to the circumstances and character of the man himself. There are three ways to make batik, such as using stamps, handmade, printing. Every type of batik has different types of patterns, and there is a repetition of a pattern and a combination of several patterns. Based on the type of batik, handmade batik has the highest price, and printing batik has the lowest prices. For batik lovers, handmade batik would want to have, but not everyone knows how to characterize the stamps batik and often mistaken in the detection of the type of batik. Thus, only a few people can distinguish the differences between the three types of batik. It is difficult for ordinary people to recognize a batik pattern. The purpose of this research is to create a prototype system that can detect the patterns of batik motifs created by handmade or stamps. Cosine similarity is used in this research to recognize the pattern and classified handmade or stamps batik. The results of this research is 95% in detecting handmade and stamp batik, then 91% in detecting sum of pattern in stamps batik.
Design of human resource information system for micro small and medium enterprises
Authors: Baswardono W , Cahyana R , Rahayu S , Nashrulloh M R
Published: December 2019

The articles aim to analyze and design of human resource information system (HRIS) for micro small and medium enterprises in Indonesia. The problem some times occurred happen in human resource when the business starts to grow. To solve this start with analyzing and design in this HRIS system using RUP (Rational Unified Process) to handle a problem such as attendance, payroll, manage employee and other Human resource problem in the scope of small or medium business. The result is a design of HRIS that can be a start for a blueprint and can be implemented for micro small and medium enterprises with condition and regulation that fit in Indonesia and also will provide the results of a design document analyzing the business needs of the process and the design of the HRIS system using the RUP method.
Design a web-based asset management information system using the straight line method for private universities
Authors: Uriawan W , Alam C N , Rifa’i A A
Published: December 2019

Universities cannot be separated from the existence of assets owned, therefore an information system is needed that functions as a tool in the asset management process. Most asset management in the private university still using Spreadsheet besides that the management of its assets is also not centralized. These problems can be solved by creating a web-based asset management information system. The purpose of this research is for design and build an asset management information system at the private university. The method used is straight line where this method is used for problems in calculating the depreciation of assets and knowing the useful life of the asset. This system can help private university administrative staff in managing assets and calculating asset value.