bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of interactive demonstration method on heat energy learning
Authors: Triayomi Ria
Published: August 2019

The purpose of this study is to determine whether there is a significant influence in using the interactive demonstration methods on heat energy learning. The research method used was an experimental method, quasi-experimental design form, and Nonequivalent Control Group Design. The sample of the research was taken by using purposive sampling technique. After the researcher conducted teaching and learning activity on the subject of heat energy in the experimental class, the obtained mean of the cognitive learning outcomes in the experimental class was 81.60. With Chi-Square test and F test, it showed that the cognitive learning result data of the experimental class and control class were distributed normally and homogeneously. After the hypothesis was tested using t-test polled variance, then the t arithmetic > t table, which was 4.32 > 1.99 t arithmetic value lies in the rejection area of H0 and the acceptance area of Ha with a 5% error rate and the degree of freedom was 74. Consequently, it can be concluded that there was a significant influence in using interactive demonstration methods on heat energy learning. If one plans using this method, it is recommended to use it for materials that are often encountered by students in everyday life.
Simulation of pension plan supplemental cost based on withdrawal rate interpolation and different benefit
Authors: Kresnawati Endang Sri , Resti Yulia
Published: August 2019

One factor that affects the supplemental cost is the probability that a participant will survive in employment to the retirement age. The probability depends on the mortality rate, the disability rate, the withdrawal rate, and the normal retirement rate. All of the rates are presented in one-year interval except the withdrawal rate. This paper uses the cubic spline interpolation to get the withdrawal rates at one year intervals, whereactuarial calculation method used is Projected Unit Credit (PUC), and pension benefits are calculated using two assumptions, namely the final average and the carrier accrued salary. The interpolation results show that first, the probability of withdrawal at the age of 25 for participants entering the pension program at the age of 20 differs from ages of 21, 22, 23, and 24. Likewise the probability of withdrawal at 30 years of age for participants entering a pension program at the age of 25 is different from ages 26, 27, 28 and 29. The same applies to other ages. The younger the age enters the pension program, the greater the unfunded liabilities that can arise. The unfunded liabilities for the final salary benefit assumption is smaller than the carrier average salary benefit assumption. The unfunded liabilities for entry at a 1-year interval are greater than 5-year intervals.
A path analysis model of students’ statistics achievement
Authors: Cahyawati Dian , Wahyudin  , Prabawanto Sufyani
Published: August 2019

Students achievement in statistics course could be influenced by various factors, both cognition and non-cognition factors. This article presents the preliminary study result about the causal relationship of some those factors, namely students’ statistics achievement (Stat_ACH), students’ attitudes toward statistics (ATS), self-regulated learning (SRL), academic achievement (Ac_ACH) and its prediction model about Stat_ACH. The hypothetical model was proposed by determining that ATS and SRL were two correlated exogenous variables and Ac_ACH as an intervening variable in its effect on the endogenous variables of Stat_ACH. A sample of 150 undergraduate active students who have taken a statistics course in their study participated in filling the questionnare as an research instrument. Validity and reliability test was conducted to the instruments. A path analysis model was used to obtain a prediction model. The results showed that students’ ATS and SRL was moderately correlated; students’ Ac_ACH was influenced by SRL variable; students’ Ac_ACH was more appropriated to be an independent variable rather than as an intervening variable. Students’ statistics achievement could be predicted through their academic achievement. The higher of students’ academic achievement the higher of students’ statistics achievements.
Investigate the effects of synthesizing techniques on the particle size reduction and thermal behaviors of carbon-based material from natural wood charcoal
Authors: Barlin  , Chang W C
Published: August 2019

In this research work, a novel investigation of the carbon-based material from natural wood charcoal synthesized with various top-down techniques on the particle size reduction and thermal behaviors. First, three powder samples were synthesized using manually by hand. Second, two powder samples were synthesized using ball milling. The particle size (length and width) were analysed using SEM micrographs. Furthermore, the thermal characterization had been carried out using thermogravimetric analysis. The results showed that the length and width of the ball milled sample are smaller than the manually milled samples (53, 74 and 105 μm) due to the higher energy mill between the ball mill and the charcoal powder. The thermogravimetric analysis showed that the samples takes places in four steps of decomposition. First stage occurred at 49.9-50°C, second at 72.58-83.69 °C, third at 268-319 °C and fourth at 689-738 °C. The ball milled samples exhibited the lower weight loss total (23.3 and 59.12%) than the manually milled samples (29.58, 34.9 and 36.39%) which is affected by the chemical composition (lignin, cellulose and hemicellulose) and inorganic substances present in the samples. As a conclusion, the ball milling gave the optimum results in terms of particle size reduction and thermal behaviors.
Study of Saros cycle and non-partial solar eclipse with Newton mechanics approach
Authors: Bama Akhmad Aminuddin , Tamara M R , Arsali  , Marini D
Published: August 2019

We have derived Saros cycle period by Newton mechanics approach using a method that had been usedby Chalub. We got the result approximately 6597,1 day; with the error comparedto Saros cycle (6585,3 day) of approximately 0,1792%. For non-partial solar eclipse case, we too have derived the equation to relate between this sun eclipse and geometrical parameter of Earth, Moon, and Sun mathematically. This equation indicates that for total sun eclipse, the umbra’s radius P on earth surface must have positive sign, whereas negative sign for annular sun eclipse. To test this equation, we compare it to a recorded (past or predicted) non-partial solar eclipse. The result indicates appropriateness for total and annular sun eclipse, but it does not appropriate for hybrid sun eclipse as we anticipated that is the magnitude of umbra’s radius P for this eclipse must near zero.
Application of advanced research WRF model using tropical (New Tiedtke) scheme and Kain-Fritsch scheme in predicting short-term weather in Palembang and its surrounding areas
Authors: Satya Octavianus Cakra , Arsali  , Mandailing Puad Maulana , Kaban Hadir
Published: August 2019

The New Tiedtke and Kain-Fritsch schemes in WRF-ARW had been applied separately for the case of short-term weather predictions in Palembang and its surroundings from 1 to 7 December 2017. The WRF-ARW predictions compared to observation data at SMB II station showed that the Kain-Fritsch scheme gave better results than the New Tiedtke scheme either for temperature (MAE = 1.24 ° C to 1.31 ° C, RMSE = 1.49 ° C to 1.60 ° C, and MAPE = 4.46 to 4.67) or for relative humidity (MAE = 6.24% to 6.54%, RMSE = 7.61 % of 8.28%, and MAPE = 8.16% for 8.61%). However, for precipitation predictions even from dichotomous test the FBI value obtained by the Kain-Fritsch scheme (FBI=2.6) is better than that by the New Tiedtke scheme (FBI=3) with a FBI value of 3, both schemes could not predict precipitation well (ACC = 0.67 to 0.64, TS = 0 to 0, POD = 0 to 0, FAR = 1 to 1).
Calculation of burnup fuel cell uranium metallic with carbon dioxide cooled
Authors: Susanty Enda , Ariani Menik , Su’ud Zaki , Monado Fiber
Published: August 2019

This article presents the calculation of uranium metallic fuel cell (U-10%Zr) to be used in carbon dioxide cooled Gas-cooled Fast Reactor (GFR). This fuel cell is a cylindrical cell with a 1.4 cm diameter. The fuel cell is tested without enrichment and enrichment of 1-10%. Calculation of fuel cells based on neutron transport equation using SRAC. The calculation parameter observed is the value of infinite multiplication factor (K-inf), conversion ratio, and Pu-239 atomic density. The results of the fuel cell calculation with 6% enrichment showed the K-inf and conversion ratio is relatively stable during burn-up history. While the largest atomic density of Pu-239 occurs in fuel cells without enrichment because U-238 atoms undergoing transmutation to Pu-239.
Synthesis of polyvinylpyrrolidone/mangosteen pericarp extract (MPE) fibered particles using electrospray
Authors: Rezeki Y A , Wahyuni N , Munir M M , Khairurrijal K
Published: August 2019

The electrospray method was used to produce polyvinylpyrrolidone (PVP)/mangosteen pericarp extract (MPE) solids. The concentrations of PVP/MPE were 3 and 4 wt.% in ethanol solvent with the mass ratios of PVP/MPE of 10:0, 8:2, and 6:4 (w/w). The surface morphology of PVP/MPE solids was investigated by an optical microscope and a scanning electron microscopy (SEM). The PVP/MPE precursor solution with the concentration of 3 wt.% and the mass ratio of 8:2 produced PVP/MPE fibered particles. From its SEM image, the particles and fibers of the PVP/MPE fibered particles had average diameters of 819 and 84 nm, respectively. The FT-IR spectra of the PVP/MPE fibered particles showed that MPE was encapsulated in PVP matrix as the PVP/MPE fibered particles had sharper peaks for the carbonyl, alkene, and amide groups.
Analysis of Kepler’s law to the movement of celestial bodies
Authors: Fatimah Galuh Titi , Marini Dian , Supardi  , Bama Akhmad Aminuddin
Published: August 2019

Unity of planetary movement theory from Newton’s law and Kepler’s law shows the orbiting motion of the planet to the sun. Kepler’s law illustrates the movement of planets orbiting the sun, assuming the sun is silent, thereby exposing the path of the orbits of planets that are often encountered so far. In fact, the sun also moves towards a certain center, so that the form of a planetary orbital path that is so closed is not a reflection of the actual movement of the planet. When the sun moves then the movement of the planet is not an elliptical but rigid. In addition the earths movement orbiting the sun is not as simple as it is described, because it is not just the earth that orbits the sun but there are other celestial bodies that also orbits the sun. So it is necessary to show the relationship of the movement of other planets to the movement of the earth around the sun. The purpose of this study is to find out the relation between the movement of other planets to the earths motion orbiting the sun and to know the true orbit path of the planets as the sun moves too. From this study, it can be seen that the use of Kepler’s law equations and Newton’s laws that have existed so far is not for the actual movement of the solar system, because many factors influence. During this time, the use of Kepler’s law and Newton’s law for the movement of the earth and the sun always considered their physical conditions ideal, assuming the sun was silent. The actual conditions of the sun moving, the shape of the trajectory of the movement of celestial bodies is not elliptical but rigid.
The effect of milling time on the structure properties and morphology of aluminium powder from construction industry waste milled using high energy milling
Authors: Ilahi Ratu Inayah , Arsyad Fitri Suryani , Sari Dwika , Jannah Miftahul
Published: August 2019

The effect of milling time on the structure and morphology of aluminum frame powder has been investigated. In this study, aluminum was made in aluminum powder, as a raw material for making bipolar plates in the Proton Exchange Membrane Fuel Cell (PEMFC) technology. Aluminum powder is synthesized using high-energy milling (HEM) with variations in milling time for 10, 20, 30, 40, and 50 minutes. Aluminum powder that has been milled, is characterized using X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM). From the results of XRD characterization, an aluminum frame that is milled for 10-20 minutes has an aluminum phosphide phase. Whereas for an aluminum frame that is milled for 30, 40 and 50 minutes has an aluminum phase Rudashevskyite. From the results of XRD also obtained, as aluminum frame has a cubic crystal structure with lattice parameters α = β = γ = 900, and aluminum powder rang each has a crystal size of 258.31, 865, 218.2, 560, and 255.9 Ǻ for 10 milling times, 20, 30, 40, and 50 minutes, so it can be concluded that the size of the aluminum frame powder crystal fluctuates. While from the results of SEM, aluminum nanoparticle powder obtained from the nanosheet structure, where the gray one is aluminum particles and the black one shows the presence of other elements. The composition of order 94% aluminum nanoparticles is pure aluminum and 6% other elements, this is reinforced from the SEM image which looks more dominant gray.
Surface Morphology Properties Doped RuO2 (0, 2, 4, 6%) of Thin Film LiNbO3
Authors: Irzaman  , Zuhri Mahfuddin , Novitri  , Irmansyah  , Setiawan Ardian Arif , Alatas Husin
Published: August 2019

Successful LiNbO3 film was prepared with the variation of 0%, 2%, 4%, and 6% RuO2 concentration and annealing temperature variation above the p-type silicon substrate (100), using the CSD method with the spin coating at 8000 rpm for 30 seconds in solubility 2 M. Films in annealing at 850 °C for 8 hours with a temperature increase of 1.67 C/min. Samples were characterised using SEM and EDX spectrometer. We have obtained the morphology nonhomogenous surface and element stoichiometry. LiNbO3 thin film is a potential material for light sensors.
Dark matter hypothesis to maintain theory of gravity
Authors: Meidina Wardah Intan , Supardi  , Bama Akhmad Aminuddin
Published: August 2019

In this paper, it will be explained pedagogically about the necessity of the emergence of the hypothesis of dark matter in an effort to maintain the existing theory of gravity. Astronomical observations of the rotation of stars in the center of galaxies show very large deviations from the predictions of existing gravitational theories. To maintain the theory of gravity, a new hypothesis is needed, i.e. by emerging the concept of dark matter. Dark matter is thought to play a major role in its interaction with gravity throughout the universe and is responsible for the regularity of the rotation speed that is (almost) constant from all galaxies in the universe.
Effect of temperature sintering on physical properties, hardness and crystal structures of ceramic TiO2 doped with 2 % Fe2O3
Authors: Umia Fika , Ramlan  , Sardjono Priyo , Muljadi  , Suprapedi
Published: August 2019

The ceramic TiO2 doped with 2 % weight of Fe2O3 has been prepared by using powder metallurgy method. The experimental research begins with the preparation of TiO2 powder mixed according with Fe2O3 powder then calcined at 1050°C for one hour. Then the calcined powder is crushed and mixed with celuna binder WE-518 as much 3% weight and compacted by using hydraulic press machine with 8 tons force. The sintering temperatures were varied starting from 1150 °C, 1200 °C and 1250 °C. The characterization of sintered samples includes: testing of its physical properties (density and porosity), hardness and microstructure analysis (X-Ray Diffraction). The results of the characterization show that the optimum of sintering temperature was achieved at the temperature 1250 °C, the results were obtained such as : density value = 2.60 g/cm3 and porosity value = 17.8 %. The result of hardness testing shows that the highest value of hardness is 292 Hv at sintering temperature 1250 °C. The result of XRD shows that it was found TiO2 phase as dominant and minor phase that is TiO2 rutile.
Effect of various sintering temperature of ceramic TiO2 on physical properties and crystall structure
Authors: Mulyadi  , Ramlan  , Nur’ Aini Siti , Djuhana
Published: August 2019

Titanium dioxide has been made by using sintering method with variation of temperature sintering. This method uses 100 % of Titanium dioxide powder as the raw material. The Titanium dioxide powder was pulverized by using High Energy Milling for one hour and continued with compacted to form a pellet by dry pressing with 8 tons force. Then the pellets were sintered by using electrical furnace with variation of temperature of 700°C, 850°C and 1000°C. The characterization of sintered samples includes measurement of density, porosity, hardness and XRD. The results show that the sintered 700°C sample has the smallest density of 1.94 g/cu.cm and the largest porosity 20 % and hardness 228 Hv. For the sintered 1000°C samplehas greatest density of 2.38 g/cu.cm and smallest porosity of 15.9% and hardness 276 Hv. The results of the phase anlysis with XRD show that the dominant phase is anatase and minor phase is rutile
Analysis of peak ground acceleration (PGA) using the probabilistic seismic hazard analysis (PSHA) method for Bengkulu earthquake of 1900 – 2017 period
Authors: Puteri Delita M , Affandi Azhar K , Sailah Siti , Hudayat Nurul , Zawawi Mahdi Kokab
Published: August 2019

This study was aimed to find out and analyze Peak Ground Acceleration (PGA) in order to mitigate the earthquake. The PGA map resulted was an acceleration map on bedrock with a probability exceeding 10% and 2% with the Probabilistic Seismic Hazard Analysis (PSHA) method for PGA in 50 years. The software used to analyze the Probabilistic Seismic Hazard Analysis (PSHA) method is USGS-PSHA. The data used was in the form of historical earthquake data from 1900 to 2017 and a depth of 1 km to 300 km. Earthquake magnitude ≥ 4.5 Mw with a research limit of 2.53° - 7.58° SL and 96.1° - 106.1° EL from the International Seismological Center (ISC) earthquake catalog, ISC-EHB Bulletin, United States Geological Survey (USGS) and The Geophysical Climatology Meteorology Institution (BMKG), a radius of 500 km from the border of Bengkulu Province. The results show that the most earthquakes for shallow depths with a magnitude of 4.5 Mw - 5.9 Mw as much as 2805 times, while for medium depths at magnitude 4.5 Mw - 5.9 Mw as much as 642 times. The probabilistic calculations exceeding 10% are 0.24 gal - 0.86 gal and probabilistic calculation exceeding 2% is 0.36 gal - 1.35 gal. The areas exposed to the danger zone are Lebong, Rejang Lebong, Kepahiang, Mukomuko, North Bengkulu and Bengkulu City. Whereas the regions included in the medium zone are Seluma and Bengkulu Tengah. And the areas of the safe zone are Kaur and South Bengkulu.
Effect of composition of LiMn2O4 cathode sheet on the electrochemical performance of lithium ion battery
Authors: Liasari Beta Riana , Bangun Jorena , Priyono Slamet , Ramlan
Published: August 2019

The effect of composition of LiMn2O4 sheet on the electrochemical performance of lithium ion battery has been studied. LiMn2O4 powder is synthesized by solid state reaction method using raw material such as LiOH.H2O and MnO2. Raw materials are stoichiometrically mixed and milled using planetary ball milling for 4 hours to become precursor. The precursor is sintered using a muffle furnace at 800 °C for 4 hours in a free air atmosphere. The sintered material is pulverized and sieved 200 mesh to form a fine LiMn2O4 powder. The material is analyzed by XRD to determine the phase and crystal structure. Powder is prepared for sheet by mixing with PVDF binder and carbon black additive in various ratio such as 85:10:5, 88:8:4 and 90:7:3. After becoming slurry, the slurry was coated onto Al foil with 300 µm in thickness and dried at 70 °C for an hour. The sheet is assembled into a half cell battery with Li metal as the counter electrode and LiPF6 as liquid electrolyte. The battery cell is measured by using the automatic battery cycler WBCS 3000 to determine the electrochemical performance. The measurement showed that samples with composition 90% active material has highest capacity with 3.6 mAh but gives bad cycle.
Effect of polymer binders on the electrochemical Performance of Al-doped lithium titanate electrode
Authors: Priyono S , Sari T D , Ramlan  , Subhan A , Prihandoko B
Published: August 2019

The investigation of polymers as binders of Al doped Li4Ti5O12 for Li-ion battery electrode is reported. Polimer binders such as Polyvinylidene fluoride (PVDF), polyvinyl alcohol (PVA), and Polytetrafluoroethylene (PTFE) were used to make electrode sheet. Al doped Lithium Titanate (Al-doped Li4Ti5O12) were used as electrode powders. Al doped Li4Ti5O12 powders were synthesized from LiOH.H2O, TiO2 and Al2O3 via solid state reaction. X-ray diffraction (XRD) was used to analysed phase and size of particle. Electrode sheets were manufactured by used active material, binders, and acetylene black in ratio 85:10:5 wt%. Electrode sheets were cut and assembled into coin cell batteries. Coin cell samples were characterized by EIS, cyclic voltammetry and charge-discharge to get electrochemical performance. XRD result reveals that there are two phases formed from final product such as Li4Ti5O12 and rutile TiO2. EIS diagram showed that sample with PTFE binder has the best conductivity with 3.10−5 S/cm. While, cyclic voltammetry and charge-discharge test showed sample with PVDF binder has the best chemical performance with good redox peaks and highest specific capacity about 110 mAh/g.
Crystalline structures properties doped RuO2 (0, 2, 4, 6%) of thin film LiNbO3
Authors: Setiawan Ardian Arif , Novitri  , Irzaman  , Zuhri Mahfuddin , Irmansyah  , Alatas Husin
Published: August 2019

Lithium Niobate (LiNbO3) can be applied as a thin film coating because it has superior piezoelectric, optoelectronic, pyroelectric, and photorefractive properties. The growth of LiNbO3 thin film using Chemical Solution Deposition (CSD) method with spin coating technique speed of 8000 rpm for 30 seconds on a p-type silicon substrate (100) with variations in concentration of RuO2 container (0%, 2%, 4%, 6%) and annealing temperature (750 ºC, 800 ºC, 850 ºC). The annealing temperature is kept on hold for 8 hours with an increase of 1.67 ºC/minute. The result of LiNbO3 of the analysis using the Cramer and Cohen method obtained hexagonal crystal structure (α = β = 90º and γ = 120º) with a lattice parameter value of 5.3856 Å to 5.6566 Å and c lattice parameter value of 15.4054 Å to 17.8404 Å.
Isolation of active compounds from the leaf extract of patah kemudi (Abroma augusta L.) and its anti-inflammatory activity
Authors: Latief M , Amanda H , Utami A , Muhaimin  , Nurhayati
Published: August 2019

Patah kemudi (Abroma augusta L.) is one of the shrubs that live on the edge of a river. A. augusta contains several secondary metabolite compounds including alkaloids, triterpenoids, steroids and flavonoids. The aim of this study was to isolate the compounds contained in the leaves of Abroma augusta and determine anti-inflammatory activity. Extraction and fractionation were performed by multilevel maceration. Isolation of compounds was carried out by column chromatography. The anti-inflammatory activity test was done using the Winter method. The n-hexane extract was separated by vacuum column chromatography and continued with gravity column chromatography to obtain isolate 8.1, which was then characterized using UV-Vis and IR spectrophotometer. The results of UV-Vis spectrophotometer on isolate 8.1 showed absorption at a maximum wavelength of 268 indicating a conjugate double bond which may be an aromatic originating from steroid compounds. While, the results of IR spectrophotometer characterization from isolate 8.1 manifested the presence of steroid compounds. The results of the activity test of isolate 8.1 with a dose of 10 mg presented the best anti-inflammatory activity compared to the positive control of diclofenac sodium. From the results of the GCMS shows that isolates contain γ-sitosterol compounds with a value of m/z 414.
Biosorption of Cu(II) onto algae biomass (Oscillatoria Splendida) isolated from swamp water ecosystem in Palembang, South Sumatera
Authors: Mohadi Risfidian , Setiawan Doni , Zulkifli Hilda
Published: August 2019

Studies of adsorption of Cu(II) on algae biomass (Oscillatoria Splendida) isolated and cultured from algae swamp ecosystem in South Sumatera have been carried out. These studies included determination of pH and kinetic biosorption at various contact time, isotherm and biosorption capacity of interaction between Cu(II) onto algae biomass (Oscillatoria Splendida). The result showed that the optimum pH was 5, and the optimum contact time was 30 min. Biosorption capacity of algae biomass (Oscillatoria Splendida) toward Cu (II) was 55.15 mg/g and agree to Pseudo-Seconds-Order kinetic model with the rate of reaction k2 is 0.00642 mg g−1 min−1 and the adsorption thermodynamic agree to the Langmuir’s model.
Tuning the stability of red color natural pigments in fruit extracts by pH control
Authors: Yuliati Leny , Juliana  , Indrawati R
Published: August 2019

Natural pigments have been recognized as potential sources for natural colorants and visible light absorbers. Unfortunately, most natural pigments have problems with the stability, which limited their potential uses for various applications. In this study, extraction of five types of red fruits, which were tomato, watermelon, strawberry, carrot, and papaya, was carried out by a slow juicer. After drying by a freeze dryer, the stability of each extract was then monitored by color measurements at various pH of 1–10 for 7 days. The results showed that the stability of the pigments was affected by the pH. However, most of the pigment extracts still suffered from the stability issue as the red color scales were found to decrease with the increase of the storage time in most any pH conditions. Particular attention was made to the strawberry extract that could be successfully stabilized at pH of 1. In addition to its stability, the strawberry extract also gave the highest red color scale among all the investigated extracts. This result suggested that the stability of the strawberry extract was tunable by the pH control and thus, its potential use as a red color source for various applications could be expected.
Development of potensiometry method for Zn analysis
Authors: Suheryanto  , Sari Rani Nawang , Hariani Poedji Loekitowati
Published: August 2019

In this research, focus for analysis Zn ion using a concentration cell potentiometry method with a Hantexmultimeter. Concentration cells are electrochemical cell circuits where the same type of solution is used but different concentrations, the more concentrated solution being the more dilute cathode and solution to the anode. So that the flow of electrons from the dilutes solution to concentrated occurs until equilibrium is reached. The multimeter connected with computer to display data processing so the analysis be easier. This method has high accuracy 98.20% and precision 0.45%.This potentiometry method can be used as an alternative method of Zn analysis.
Film (patch) based on starch compound hydrolise by amylase from saliva and bacteria
Authors: Miksusanti  , Herlina  , Fithri A.N , Yuniar  , Novalin V , Julinar
Published: August 2019

Research on the determination of amylase enzyme activity on hydrolysing film (patch) made from sugar palm starch with the addition of STPP and Temu putih (curcuma zedoaria) freeze drying powder have been done. The purpose of this study was to determine amylase enzyme activity of saliva and amylase from bacteria in hydrolysis of sugar palm starch and edible film made from palm starch with the addition of STPP and Temu putih freeze drying powder. Amylase enzyme activity was analysed using UV-Vis spectrophotometer and DNS reagent. Determination of amylase enzyme activity in hydrolysing edible film was carried out by reacting enzyme with various edible film at optimum condition. The result of amylase enzyme activity from saliva and bacteria was obtained at temperature 35 °C, pH 7, substrate concentration 2.5%, and incubation time 95 min. The enzyme was reacted in various concentration against edible film at optimum condition. Amylase enzyme activity of saliva gave optimum edible film hydrolysis in the addition of STPP of 10.26 unit/mL, whereas the best enzyme activity of amylase from bacteria achieved with the addition of STPP and 3% freeze drying powder of Temu putih at 23.09 units/mL. Data analysis using one-way analysis of variance obtained F-value less than F-table at significance level 0.05. The result implied there is no significant difference on amylase enzyme activity from saliva and bacteria when it used to hydrolyse sugar palm starch and edible film from sugar palm starch with the addition of STPP and Temu putih freeze drying powder.
Synthesis and characterization schiff base and complexes with Copper (II) and Iron (II) and their application as antibacterial agents
Authors: Hidayati N , Fatma  , Purwaningrum W
Published: August 2019

The Schiff base N-(2-hydroxybenzylidene)chitosan and its complexes with copper(II) and iron(II) were synthesized and applied as antibacterial agent. The Schiff base and its complexes characterized by UV-Vis, FTIR spectrophotometer and XRD diffractometer. Antibacterial activity of the Schiff base and its complexes toward Escherichia coli and Staphylococcus aureus bacteria were assessed by paper disc diffusion method. Electronic transition indicated the absorption of azomethine group from Schiff Base and absorption of d-d transition from metal ion. FTIR characterization of Schiff base indicated the azomethine group have been formed. Absorption Schiff base shifted indicating coordinated to metal ion. X-ray diffractometer studies show the formation of complexes decreased of cristalinity of chitosan. The complexes of copper(II) and iron(II) with N-(2-hydroxybenzylidene)chitosan have antibacterial activities bigger than the Schiff Base or pure chitosan attributed to the increased lipophilic nature of the complexes arising due to chelation.
Monitoring of formulation and hazardous ingredients of residential insecticide which sold in Palembang
Authors: Khairunnisa Mia Hayati , Ghiffari Ahmad , Anwar Chairil , Dalilah Dalilah
Published: August 2019

The insect-borne disease is one of health problem. The high mortality and morbidity rates of disease mostly controlled on chemical insecticide. Precaution was needed on selecting the residential insecticides since it can also harm human. This study was to identify the formulation and active ingredients of residential insecticides. This was a descriptive study with an observational design. The sample used was all insecticides sold in location of Palembang Square Mall. Variables observed were the insecticides’ forms, the insect targets, the active ingredients, and the class of toxicity. As conclusion, there were 57 type of insecticides and 14 type of active ingredients found in the location. Most insecticides were from liquid synthetic pyrethroid group, unfortunately categorized in the hazardous class. Further research is necessary to determined whether the insecticide already effects on human health.
Protection of mild steel from corrosion using methanol extract of avocado (Persea americana mill) seeds in a solution of sulfuric acid
Authors: Gusti D R , Lestari I , Farid F , Sirait P T
Published: August 2019

Avocado seeds have been studied for use as corrosion inhibitors of mild steel in a solution of 0.75 M sulfuric acid. Corrosion inhibition efficiency at a concentration of 10 g / L avocado seed extract (ASE) was obtained at 74.56% with weight loss method and 68.38% with potentiometric polarization method. Corrosion inhibition efficiency was found to be greater with increasing ASE concentration. Polarization studies show that the avocado seed extract is a mixed corrosion inhibitor. SEM images on mild steel with the addition of ASE showed the formation of a thin layer on the mild steel surface. OH and CN functional groups appear on the FT-IR spectrum of ASE. These functional groups interact with iron on the steel surface to form a thin layer that can inhibit corrosive ion attacks from sulfuric acid solutions.
Study on the anti-inflammatory properties of Karamunting (Rhodomyrtustomentosa (Aiton) Hassk.) leaf extracts
Authors: Solihah Indah , Wulandari Widya , Herlina  , Puspita Rasyid Riana Sari , Suciati Tri
Published: August 2019

Karamunting (Rhodomyrtustomentosa (Aiton) Hassk.) is one of the most widespread plants in Sumaterawhich areknown to have traditionally used as wound and infection remedy. However, research on anti-inflammatory activity is limited. This study aimedto determine the effect of antiinflammatory of Karamunting (Rhodomyrtus tomentosa (Aiton) Hassk.) leaf extracts using acute rat model (carrageenan-induced rat paw oedema). Sodium diclofenac 4,5 mg.kg−1BW as standard anti-inflammatory drug, n-hexane, ethyl acetate, and ethanol of Karamunting (Rhodomyrtus tomentosa (Aiton) Hassk.) leaf extracts each dose 200 mg.kg−1BW were administered orally to 24 Wistar rats 1 h before induction oedema and compared with a negative control given Na CMC 1%. The mean percentage inhibition of paw volume of rats treated with sodium diclofenac was 64,82%, followed by n-hexane extract with 44,75%, ethyl acetat extract with 56,93%, and ethanol extract with 63,56%. All extract have similar antiinflammatory effect with sodium diclofenac (p>0,05). This result suggest that all Karamunting (Rhodomyrtus tomentosa (Aiton) Hassk.) leaf extracts have antiinflammatory properties comparable withstandard drugs.
Antioxidant activity of isolated compound from perepat roots (Sonneratia alba)
Authors: Latief M , Utami A , Amanda H , Muhaimin  , Afifah Z
Published: August 2019

Perepat (Sonneratia alba) is one of the mangrove plants found in Tanjung Jabung Timur, Jambi Province. Research on perepat plants has been widely carried out on leaves, fruit and bark, but there is no research on perepat roots, so it is necessary to do research on perepat roots. This study aims to determine the compounds found in ethyl acetate extract from roots which have antioxidant activity. Extraction and fractionation of perepat roots were carried out in multilevel maceration. The isolation technique was carried out using vacuum column chromatography and gravity column chromatography. The isolated compound was identified using UV-Vis spectrophotometer, FT-IR and NMR. Antioxidant activity test of the isolated compound was carried out by DPPH method. Characterization using UV-Vis gives maximum absorption at wavelengths 268and 313 nm. While the characterization with FT-IR provide information that the isolate containing functional groups of OH, C=O, CH3 and CH2. Further identification using NMR suggests that isolate are a mixture of stigmasterol and ß-sitosterol compounds, known as phytosterols. Antioxidant activity testing of ethyl acetate extract and isolate gave IC50 values of 223.67 and 439.71 ppm, respectively, indicating that these compounds were classified as less active but still potential as antioxidants.
Estimation of mixed layer depth from argo float data in Makassar strait during el niño southern oscilation
Authors: Amalia F , Mubarrok S , Mandang I
Published: August 2019

Makassar Strait is a pathway of water mass passing trough from the Pacific Ocean to the Indian Ocean. Makassar Strait is also one of the waters in Indonesia which passed by Indonesian Throughflow (ITF). Movement of water masses due to the ITF, wind system, and complex bathymetry conditions will cause the movement of vertical water masses (mixing). This makes the upper layers homogeneous, the objective of this study is to assess the variation of MLD using Argo Float data adjusted for ENSO (El Niño Southern Oscilation) events, under El Niño, La Niña, and normal conditions. MLD determination using temperature gradient criterion with value ≤ 0,1 oC/m. The data processing using Ocean Data View 5.0.0 software shows that the depth of homogeneous layer in Makassar Strait waters during El Niño years is various, between 37,73 – 73,62 m with temperature 25,7 - 28,99 oC. During La Niña, MLD found varying around 30,59 – 97,89 m with temperature profile slightly colder (26,7 – 29,8 oC). And during normal year, MLD located around 28,55 m to 112,98 m, shallowest and deepest from all data set, respectively. Average value of MLD in is vaguely normal deeper than La Niña and El Niño condition, as it should be shallower, showed that temperature gradient criterion with value ≤ 0,1 oC/m is not quite good to determine the MLD layer in Makassar Strait.
Kinship of the swamp buffalo (bubalus bubalis) in Tanjung Senai, Ogan Ilir, South Sumatra based on morphological characteristics
Authors: Windusari Yuanita , Hanum Laila , Setiawan Arum , Pratama Rahmat , Sari Desi Puspita , Palupi Rizki
Published: August 2019

Research conducted for observe phylogenetic relationship swamp buffalo (Bubalus bubalis) Ogan Ilir regency, South Sumatera based on morphological characteristic. The Sampling done by using a survey method and inventory in the field (on-farm) to obtain data of the characterization and swamp buffalo morphological. The result indicate that there are six variant, namely are BlackBuffalo, Lampung Buffalo, Red Buffalo, Dungkul Buffalo, Straight Buffalo, and Tunjang Langit Buffalo. Black Buffalo has black body colour and horns bent backwards. Lampung has black body colour and horns bent upwards. Red Buffalo has red body colour and horns bent upwards. Dungkul has black body colour and horns bent downwards. Straight has black body colour and horns bent straight to the side. Tunjang Langit Buffalo has black body colour and horns bent upwards and downwards.
Comparative photocatalytic performances towards acid yellow 17 (AY17) and direct blue 71 (DB71) degradation using Sn3O4 flower-like structure
Authors: Huda A , Ichwani R , Handoko C T , Bustan M D , Yudono B , Gulo F
Published: August 2019

Microsphere Sn3O4 flower-like structure has been successfully synthesized using a novel microwave-assisted hydrothermal method and comprehensively characterized by X-ray diffraction (XRD), field emission gun scanning electron microscope (FEG-SEM) and UV Vis spectrophotometer equipped with diffuse reflectance spectroscopy (UV-Vis DRS). In order to examine its photocatalytic performance, two synthetic azo-based dyes, acid yellow 17 (AY17) and direct blue 71 (DB71), have been used as organic pollutant models degraded under visible-light illumination. The results show that the negative charges of Sn3O4 produce higher efficiency photocatalytic activity on DB71 degradation compared to that on AY17 degradation. Further investigation has confirmed that the adsorption capacities played the main role in determining photocatalytic performance and differentiated the quantum yield of dye degradation. Moreover, the different adsorption capacities are generated by the formation of electrostatic interaction and repulsion between surface charge of Sn3O4 and dyes functional groups.
Influence of environmental parameters on the shrimp catch in Banyuasin Coastal Water, South Sumatra, Indonesia
Authors: Fauziyah  , Agustriani F , Purwiyanto A I S , Putri W A E , Suteja Y
Published: August 2019

Shrimps are species with short life cycle and particularly sensitive to environmental conditions since both marine and coastal habitat. However, changes in some environmental parameters were thought to be the most important which can affect the shrimp catch. This research aimed to determine the environmental parameters that most influence the shrimp catch in the Banyuasin Coastal Waters. Sampling for shrimp catch was conducted at 11 stations in Banyuasin Coastal Water used a trammel net. In situ environmental parameters such as water temperature, salinity, pH, current velocity, chlorophyll-a concentration, depth, substrate types, phosphates and nitrates concentrations were recorded during each sampling time. The influence of environmental parameters on the shrimp relative-abundance was analyzed by stepwise multiple regression and the significance level adopted was p < 0.05. The analysis results indicated that approximately 64.5% of the variation in the relative abundance of shrimp was explained by pH and substrate types. There were a strong correlation between the relative abundance of shrimp and in situ environmental parameters (0.50 < adjusted R2 = 0.645 ≤ 0.75), particularly pH and substrate types. The shrimp relative-abundance was positively correlated with pH, but negatively with substrate types. Thus, pH and the substrate types were determinant factors to the shrimp relative-abundance in the study area.
Distribution of phytoplankton diversity and abundance in Maspari island waters, South Sumatera, Indonesia
Authors: Rozirwan  , Iskandar I , Hendri M , Apri R , Supardi  , Azhar N , Mardiansyah W
Published: August 2019

Phytoplankton diversity is one of eutrophication indicator in Maspari island, south Sumatra, but its existence is strongly influenced by the physical-chemical parameters of the waters. This study aims to determine the distribution of phytoplankton diversity and their relationship with physical-chemical parameters in the waters of Maspari island. The methodology of research carried out was the physical-chemical parameter data collection, and phytoplankton samples were taken randomly on the surface of the water of 20 stations. Samples were identified types, analysed diversity, dominance and abundance calculations. For the relationship between diversity and abundance of phytoplankton with physical-chemical parameters of water carried out by principal component analysis (PCA). The results obtained that some of the physical-chemical parameters of Maspari Island waters have high variations such as turbidity ranging from 17,313 to 89,313 FTU. Current speed about 0.0-1,418 m.s−1. Dissolved oxygen about 3.78±0.18-6.18±0.15 mg.1−1. Nutrient concentrations such as NO3 about 0-0.28 mg.l−1 and PO4 about 0-0.2 mg.1−1, while the other parameters were smaller variations. Phytoplankton types found in four classes, namely Coscinodiscophyceae (7 species) with an abundance of 121,910.82 cell.m−3 (49%), Dinophyceae (4 species) with an abundance of 54,649.68 cell.m−3 (26%), Bacillariophyceae (3 species) with an abundance of 56,050.95 cell.m−3 (23%), and Fragilariophyceae (1 species) with an abundance of 5,605.09 cell.m−3 (2%). Diversity index shows low to moderate categories, while dominance in categories tends to dominate. PCA results showed that the physical-chemical parameters of the Maspari island waters of the identifier is the temperature, density, nitrate, salinity, DO and phosphate.
Identification of surface macro debrisin river flow and estuary of Musi River, South Sumatera Province, Indonesia
Authors: Maherlsa R , Purwiyanto A IS , Agustriani F , Putri W AE , Fauziyah  , Ferdiansyah
Published: August 2019

The Musi River is one of the largest and densest rivers in South Sumatra Province, Indonesia. Various activities are found along the river flow, in the upstream to the estuary, causing the river to be vulnerable for input of macro debris. This research aims to identify the type of material and the size of macro debris found along the river flow to the estuary of the Musi River. The research was carried out by performing macro debris sampling using a net operated with a manta system. This research used 10 stations that represent activities along the flow with tracking lengths as far as 87 km to the estuary. The results showed that the highest numbers of macro debris were found at Station 2 (fisherman settlement) which was is 33 items. The material of macro debris was is dominated by plastic material in all stations, with litter codes food packaging and had have medium size (2.5-10 cm).
Big Bang Nucleosynthesis and the Lithium Problem
Authors: Bertulani C.A.
Published: August 2019

I briefly describe the cosmological lithium problems followed by a summary of our recent theoretical work on the magnitude of the effects of electron screening, the possible existence of dark matter parallel universes and the use of non-extensive (Tsallis) statistics during big bang nucleosynthesis. Solutions within nuclear physics are also discussed and recent measurements of cross-sections based on indirect experimental techniques are summarized.
The role of nucleon knockout in pre-equilibrium reactions
Authors: Chimanski E V , Carlson B V , Capote R , Koning A J
Published: August 2019

Nucleon-induced pre-equilibrium reactions are predominantly direct reactions. At low incident energies, excitation of all but the lowest energy collective states can be well described in terms of one-step reactions that produce particle-hole pairs. As the incident energy increases, the probability of exciting a nucleon to the continuum rather than to a bound particle state also increases. These knockout nucleons can escape the nucleus or induce secondary collisions that create still other continuum or bound particle-hole pairs. We discuss their role in pre-compound nuclear reactions here, first in a semiclassical Monte Carlo description of the reaction and then in a quantum one-step calculation.
Searching signature of neutrino-nucleus coherent scattering with Mössbauer Spectroscopy
Authors: Marques C , Dias G S , Chavez Sanchez H H , Duarte S B
Published: August 2019

The Mössbauer spectroscopy is proposed as an alternative experimental technique to be pursued in the detection of Coherent Elastic ν-Nucleus Scattering (CENNS). The neutrino transferred energy in the neutrino-nucleus interaction causes a perturbation at the nuclear level structure of the Mössbauer isotope, leading to a displacement of the isomeric peak of the electromagnetic resonance. We calculate this isomeric shift correction due to the occurrence of CENNS and show that this quantity can be measured with enough precision in a typical Mössbauer spectroscopic experiment. We also shown that a reasonable number of events is expected and allow to extract the correction in the isomeric shift in a typical neutrino reactor flux. This isomeric shift correction is pointed out as a figure of merit for signature of CENNS in our proposal.
Ionizing radiation effects in a rectifier circuit
Authors: Bôas A C V , Guazzelli M A , Giacomini R C , Medina N H
Published: August 2019

This work aims to study the effects of ionizing radiation on a half-wave rectifier circuit. The diodes of the circuit, rectifier and Zener, were exposed to X-rays of 10 keV of effective energy. The characteristic curves of both diodes were evaluated before and after being subjected to cumulative total ionizing dose (TID) effects. The accumulation of charges in the dielectric structures of the diodes alter their individual functionalities, but the changes verified in the rectification were irrelevant. In this study, three irradiation methods were used to correlate the physical mechanisms responsible for the effects caused by radiation with variations in the electrical parameters of the devices and the efficiency of the rectifier circuit.
Ions concentration in blood samples of SJL/J dystrophic mice strains using X-ray fluorescence spectrometry
Authors: Giovanni D N S , Almeida M R , Zamboni C B , Metairon S , Balduino K N , Suzuki M F , Bueno C R
Published: August 2019

Star This study proposes an investigation of ions in whole blood of the dystrophic animal model SJL/J (mice strain with dysferlin protein deficiency) and in the control group (C57BL/6J) using the Energy Dispersive X-ray Fluorescence (EDXRF) spectrometry technique. The comparison between control and dystrophic mice results shown an increase in blood for P, S, K and Fe (p < 0.05) while a decrease in Ca (p < 0.05). This elemental analysis will contribute to evaluate the best diagnostic, care and treatment procedures, for the Progressive Muscular Dystrophy.