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INDONESIA
SAINS DAN MATEMATIKA
Published by Universitas Diponegoro
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Core Subject : Education,
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Articles 5 Documents
Search results for , issue "Volume 22 Issue 4 Year 2014" : 5 Documents clear
Flavonoids Production Capability Test of Tea Mistletoe (Scurrula atropurpurea BL . Dans) Endophytic Bacteria Isolates Priyanto, Jepri Agung; Pujiyanto, Sri; Rukmi, Isworo
JURNAL SAINS DAN MATEMATIKA Volume 22 Issue 4 Year 2014
Publisher : JURNAL SAINS DAN MATEMATIKA

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Abstract

Tea Mistletoe (S. Atropurpurea BL. Dans) is a medicinal plant species used as anticancer because it contains some flavonoids compounds are chalcones, c-glycoflavonols, chatechin and quercetin. The ability of endophytic bacteria to produce similar bioactive compounds with its host plant is potential source to get flavonoids compounds. This research aims to know ability of endophytic bacteria in produce flavonoids compounds in vitro. Each isolate was fermented in submerged culture with 0.1% soluble starch, 0.5% pepton, and 0.15% yeast extract medium for 5 days, then extracted with ethyl acetate. Flavonoid content of the extract then was tested qualitatively and confirmation test used thin layer chromatography. Qualitative test results showed that crude extract from isolates B4, B5, B10, B17, and B19 positive containing flavonoids. The most potent extract were B10 and B19 tested by thin layer chromatography. Two of these extracts had the same Rf value with quercetin, thus endophytic bacteria from tea mistletoe can produce flavonoids in vitro.
The Antioxidant Growth and Potency of Yeast Rhodosporidium paludigenum DUCC Y-007 on Different Mediums Kusdiyantini, Endang; Budiharjo, Anto
JURNAL SAINS DAN MATEMATIKA Volume 22 Issue 4 Year 2014
Publisher : JURNAL SAINS DAN MATEMATIKA

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Abstract

The antioxidant growth and potency of yeast Rhodosporidium paludigenum DUCC Y-007 have been studied on two treatment mediums. The yeast could grow on two treatment mediums and the dry weight results obtained during the incubation period of 120 hours were 7.17 g/L and 7.33 g/L. The concentration of reducing sugars in stabilized medium were 3.14 g/L and 3.30 g/L at 72-120 hours incubation time respectively. There were differences in pH changes during incubation time which at YPG medium, it tended to increase whereas at semi synthetic medium, the pH tended to decline. Total carotenoid on YPG medium was 50.13 µg/g cell and on the semi-synthetic medium was 197.50 µg/g cell. Antioxidant activity measured by DPPH reagent showed the results at YPG medium was 50% and at semi-synthetic medium was 61%.
Natural Polarization and Electrooptics Comparison for Evaluation of Cooking Oil Total Quality Sugito, Heri; Firdausi, Ketut Sofjan
JURNAL SAINS DAN MATEMATIKA Volume 22 Issue 4 Year 2014
Publisher : JURNAL SAINS DAN MATEMATIKA

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Abstract

In this study, the phenomena of natural polarization and electrooptics effect have been compared as alternative methods for evaluation of vegetable oil quality. The sample used in the experiment was various vegetable oils. The change of light polarization was measured using a pair of polarizer for natural polarization and in case of electrooptics with addition of induced external electric field through DC high voltage. The result has shown that both methods are able to indicate the level of various oil quality. The natural polarization is very useful for preliminary test of oil quality. In the other hand, the electrooptics has a good prospect as single physical indicator for vegetable oil quality.
Lactose Bioelectricity on A Microbial Fuel Cell System Parallel Circuit using Lactobacillus bulgaricus Adi Putra; Rahmad Nuryanto; Linda Suyati
JURNAL SAINS DAN MATEMATIKA Volume 22 Issue 4 Year 2014
Publisher : JURNAL SAINS DAN MATEMATIKA

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Abstract

Electrical energy needs in Indonesia is estimated to continue growing by 4.6% per year, and if there is nothing to be done to increase the production of electric energy, this figure will increase threefold by 2030. Microbial Fuel Cells (MFC) is one way to produce alternative electric energy by utilizing organic material as a substrate for bacterial metabolic activity that generate electricity. The aim of this study is to examine lactose bioelectricity in a parallel circuit MFC system using Lactobacillus bulgaricus to generate electrical energy. The principle of this study is bioelectrochemistry which is the chemical energy change into electrical energy involving redox reactions by utilizing microbes. This study used a dual chamber MFC system with salt bridge as a connector and conductor of protons from the cathode compartment to the anode compartment. An anode compartment contained the bacteria Lactobacillus bulgaricus and lactose substrate, while the cathode compartment contained electrolyte solution KMnO4 0.2 M and phosphate buffer solution with pH = 7. This study used a single circuit, parallel circuit 1 with 2 cells, and a parallel circuit 2 with 3 cells which were oriented to enlarge the produced electricity current. Bioelectricity of lactose produced power in a single series, parallel 1 and parallel 2 respectively were 72.58 x10-6 mWatt; 155.77 x10-6 mWatt; 270.28 x10-6 mWatt where the power generated was proportional to the parallel circuit electric current. Hence by the same potential difference, the power magnitude in parallel circuit 1 approached twice to the single circuit and the power magnitude in parallel circuit 2 approached three times to the single circuit
Speed Model Processing using Ray Tracing Method for 2D Depth Domain Migration (Pre Stack Depth Migration) on the field "AV" Evita, Anjar; Danusaputro, Hernowo
JURNAL SAINS DAN MATEMATIKA Volume 22 Issue 4 Year 2014
Publisher : JURNAL SAINS DAN MATEMATIKA

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Abstract

The research was conducted to process 2D seismic data by Pre Stack Depth Migration (PSDM) method on the field “AV”. The purpose of this study was to determine the appropriate interval velocity model to manage the PSDM methods work. Interval velocity model obtained from the initial estimate using coherency inversion velocity model is usually not convergent. Interval velocity model should be improved through several stages in order the estimated speed could be closer to the actual speed value. Some initial interval velocity model parameters should be improved to be more sensitive to lateral velocity variations for PSDM work. The method used to improve the velocity model was a horizon-based tomography using the ray tracing concept. These methods improved the layer speed and reflector geometry to produce a new interval velocity model. Model errors should be corrected by residual move out analysis. The best analysis obtained was from the fifth iteration to eliminate errors and flatten depth gathers. The proper value of the speed produced good quality images. The results of this research was PSDM Section or PSDM cross-section. PSDM cross-section has a good image quality to represent the geological structures in the earth's sub surface.

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