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Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam
Published by Universitas Riau
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Core Subject : Education,
Mathematics
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Articles 424 Documents
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TOTAL FENOLIK, FLAVONOID, DAN AKTIVITAS ANTIOKSIDAN DARI PRODUK TEH HIJAU DAN TEH HITAM TANAMAN BANGUN-BANGUN (Coleus amboinicus) DENGAN PERLAKUAN ETT RUMPUT PAITAN Rahayu, Fitri; Jose, Christine; Haryani, Yuli
Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam Vol 2, No 1 (2015): Wisuda Februari 2015
Publisher : Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam

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Abstract

Coleus amboinicus is one plant with a good antioxidant content. The concentration of antioxidant from C. amboinicus could be increased by using a treatment fermented plant extract (FPE) containing paitan grass. C. amboinicus is potential to be used as raw material to produce herbal tea such as green tea and black tea because of its high antioxidant content. The objective of this study was to analyze the total phenolics, flavonoids, and antioxidant activity from tea product of C. amboinicus. Antioxidant activity was analyzed using one method, that Ferric Reducing Antioxidant Power (FRAP). The results showed that C. amboinicus treated with FPE paitan grass had the highest total phenolic, flavonoid, and antioxidant activity content than control. The green tea produced using FPE paitan grass had the highest content of total phenolic and flavonoid i.e., 25,596 Gallic Acid Equivalent (GAE) mg/g of dry weight (DW) and 5,632 Catechin Equivalent (CTE) mg/g of DW, respectively. Antioxidant activity analyzed by using FRAP method also showed that the highest antioxidant was found in green tea treated using FPE paitan grass. It can be concluded that green tea C. amboinicus treated by FPE paitan grass is a good source of phenolic, flavonoid, and antioxidant.
METODE ITERASI BARU YANG OPTIMAL BERORDE EMPAT TANPA TURUNAN KEDUA DAN DINAMIKNYA Fitria Afri Yanti; Imran M.; Agusni '
Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam Vol 2, No 1 (2015): Wisuda Februari 2015
Publisher : Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam

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This article discusses an iterative metho d to solve a nonlinear equation, which is free from second derivative by approximating a second derivative by a divided difference. Analytically it is shown using the Taylor expansion and geometric series that this iterative metho d has a convergence of order four. Furthermore, numerical comparisons between the prop osed metho d and several well-known iterative methods of order four and free from second derivative are p erformed. By varying the initial guesses, we compare the numb er of iterations obtained by those methods to get an approximated ro ot. In addition, comparisons are also made through basins of attraction of the discussed methods.
METODE BERTIPE STEFFENSEN DENGAN ORDE KONVERGENSI OPTIMAL UNTUK MENYELESAIKAN PERSAMAAN NONLINEAR Sarbaini '; Imran M.; Asmara Karma
Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam Vol 2, No 1 (2015): Wisuda Februari 2015
Publisher : Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam

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This article discusses a mo dification of a third order Steffensen-typ e method, by adding three different weight functions into the third order Steffensen-type method, so that we obtain three different correction Steffensen-typ e metho ds. These methods are of order three and require three function evaluations p er iteration so that their index of efficiency is 1.587. Computational results show the correction Steffensentype methods are competitive enough in their class.
EKSTRAKSI DNA DAN AMPLIFIKASI ITS rDNA ISOLAT FUNGI ENDOFIT LBKURCC67 UMBI TANAMAN DAHLIA (DAHLIA VARIABILIS) Senjavi Rakhmana; Saryono '; Titania Tjandrawati Nugroho
Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam Vol 2, No 1 (2015): Wisuda Februari 2015
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Abstract

> Endophyte fungi lives in the plant tissues without causing harm to their host and has known that can produce secondary metabolite and extracellular enzyme. Fungi LBKURCC67 is an endophyte fungi that was isolated from tubers of yellow flowered Dahlia variabilis in Padang Panjang, West Sumatera. Species of fungi LBKURCC67 isolate was not known exactly because the morphology identification has been previously is appropriate for genus level. The accurate identification to known species is molecular with phylogenetic analysis. Before determine species in molecular analysis, it must extraction and amplification DNA. This research aims to optimation of DNA extraction and rDNA amplification in Internal Transcribed Spacer (ITS) regions with Polymerase Chain Reactions (PCR) methods. The DNA of fungi LBKURCC67 isolate was extract with Wizard Genomic DNA Purification kit ex Promega Corp. (Madison, USA) from cultur mycelium. The result shows extraction DNA was success from fourth days mycelia. Optimum condition for rDNA amplification with PCR were used ITS5 and ITS4 primers and 41°C annealing temperature. Electrophoresis analysis shows molecular weight of DNA isolate is 16.951 bp and molecular weight of PCR product is 583 bp.
HUBUNGAN AKTIVITAS ENZIM DAN KONSENTRASI SUBSTRAT PADA POLA DETEKSI SECARA HPLC HASIL TRANSGLIKOSILASI PINOCEMBRIN OLEH ENZIM SELULASE Trichoderma asperellum LBKURCC1 Fifira Safitri; Titania Tjandrawati Nugroho; Hilwan Yuda Teruna
Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam Vol 2, No 1 (2015): Wisuda Februari 2015
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Abstract

"> Enzymatic transglycosylation of pinocembrin was successfully carried out by cellulase from Trichoderma asperellum LBKURCC1. However, the reproducibility of the reaction is low, making detection by reverse phase HPLC (High Performance Liquid Chromatography) difficult when the enzyme activity decreases. It is believed that the initial flavonoid concentration used in the transglycosylation reaction influences the detection pattern of transglycosylation product by HPLC, when the enzyme activity is low. In this research, transglycosylation of pinocembrin was done by a concentrated extract of T. asperellum LBKURCC1 cellulase and using CMC (Carboxymethyl Cellulose) as glycosyl donor. The reaction was carried out for 30 hours at 40oC and 170 rpm shaking. Results of HPLC analysis showed that cellulase with activity of (4.3±0.2) U/mL could only obtain 1.7% conversion of pinocembrin to its glycosylated product when the substrate concentration was 6 mg/mL. At these conditions, a barely detectable HPLC peak was observed at retention time of 8.4 minutes. This peak increased noticeably when the initial concentration of pinocembrin was decreased to 0.6 mg/mL. Percent conversion of pinocembrin to its transglycosylation product was 4.3% when the initial substrate concentration was 0.6 mg/mL and the enzyme activity was (4.3±0.2) U/mL.
POTENSI EKSTRAK Cymbopogon citratus DC. DAN Mucuna bracteata DC. TERHADAP PENGHAMBATAN PERKECAMBAHAN DAN PERTUMBUHAN GULMA Borreria alata (Aublet) DC. Dewi Yuni Safitri; Siti Fatonah; Herman '
Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam Vol 2, No 1 (2015): Wisuda Februari 2015
Publisher : Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam

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Abstract

One of the environmentally friendly alternative in controlling weed is by using organic herbicides. The potential plant as organic herbicides such as Cymbopogon citratus and Mucuna bracteata, contain essential oils and allelopat. This research aimed to determine the extract influence and the best concentration of C. Citratus and M. bracteata in inhibiting the germination and growth of Borreria alata. This research used a randomized design with seven treatments i.e. control (0%), 20%, 40%, 60% C. Citratus extract and 20%, 40%, 60% M. bracteata extract. The observed data were analized using ANOVA and if significantly different followed by DMRT. The results showed that all treatments of the extract decreased the germination and growth of P. conjugatum and Borreria alata. The best extract was 40% and 60% M. bracteata that inhibit the germination and growth of B. alata.
PENGENDALIAN Ganoderma boninense OLEH Trichoderma sp. SBJ8 PADA KECAMBAH DAN BIBIT KELAPA SAWIT (Elaeis guineensis Jacq.) DI TANAH GAMBUT Rizky Alviodinasyari; Atria Martina; Wahyu Lestari
Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam Vol 2, No 1 (2015): Wisuda Februari 2015
Publisher : Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam

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Basal stem rot disease caused by Ganoderma boninense is the most destructive disease in oil palm plantation in Indonesia, especially in the peatland. The use of chemical pesticides as controlling agent is hazardous to environment and human health. The alternative to control this disease is by using biological agent Trichoderma sp. SBJ8 in the form of Ganofend biofungicide. The research were aimed to study the effectivity ofTrichoderma sp. SBJ8 isolate in suppressing in vitro growth of G. boninense, as well as to determine the ability of Ganofend biofungicide in inhibiting the growth of G. boninense on the oil palm germination and seedling. The experimental study included two cultures i.e. in vitro and in vivo using randomized design with 6 treatments: without Ganofend biofungicide treatment, 100 g Ganofend biofungicide treatment, and with immersing in Ganofend biofungicide solution for both root and seedling of oil palm. The results showed that the isolates of Trichoderma sp. SBJ8 could inhibit the growth of G. boninense in 4th day up to 65,25%. The treatment using Ganofend biofungicide was effective to decrease the mortality percentage of oil palm germination and not causes seedling death.
ANALISIS ELASTISITAS BATU BATA YANG DIBUAT DENGAN TEKNIK PEMANAS TENAGA SURYA MENGGUNAKAN REFLEKTOR CERMIN CEKUNG Anda Yani; Muhammad Edisar; Antonius Surbakti
Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam Vol 2, No 1 (2015): Wisuda Februari 2015
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The research has been conducted to investigate the quality of some bricks. The quality of the bricks was tested after heating by solar energy using concave mirror reflector on their elastic properties. The quality of the bricks after being heated was compared with the bricks that were prepared by conventional way (by heating using fire). The elasticity properties were calculated from the time propagation of the seismic wave in the bricks. The results of the research showed that the elasticity of the bricks heated using solar energy for 80 hours was 50.623 (N/m²), and the lowest elasticity heated for 10 hours was 16.530 (N/m). While the elasticity of bricks heated using fire with the distance of 0.7 meters was 72.199 (N/m²) and the lowest elasticity of bricks with the distance from fire of 0.76 meter was 32.555 (N / m²). The results also showed that the quality of the bricks was better through direct burning using fire compared to the one prepared by solar energy.
ESTERIFIKASI MINYAK GORENG BEKAS DENGAN KATALIS H2SO4 DAN TRANSESTERIFIKASI DENGAN KATALIS CaO DARI CANGKANG KERANG DARAH: VARIASI KONDISI ESTERIFIKASI Apriani Sartika; Nurhayati '; Muhdarina '
Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam Vol 2, No 1 (2015): Wisuda Februari 2015
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Fuel that becomes important requirement of Indonesian is more dwindling and will run out within the next 12 years. Therefore, the development of alternative fuels that are environmentally friendly is needed. One example of an environmentally friendly alternative fuel is biodiesel. This study aimed to synthesize biodiesel from used cooking oil by esterification and transesterification step and determine the optimum conditions. The parameters varied are the reaction esterification which weight of H2SO4 catalyst and mole ratio of oil:methanol, while temperature and reaction time was remained variable. Transesterification reaction parameters was remained variable. The analysis showed that the conversion of biodiesel was 70,35% obtained by the optimum condition of esterification was weight of H2SO4 catalyst was 3%, the mole ratio of oil: methanol was1:18, temperature was 70oC, and reaction time was 3 hours. Based on this results, it can be concluded that the used cooking oil can be used as raw material for biodiesel synthesis.
PENAKSIR RASIO DAN PRODUK EKSPONENSIAL YANG EFISIEN UNTUK RATA-RATA POPULASI PADA SAMPLING ACAK SISTEMATIK Fanny Wirastuti; Bustami '; Haposan Sirait
Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam Vol 2, No 1 (2015): Wisuda Februari 2015
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Abstract

The estimators discussed in this paper are the ratio exponential estimator, the product exponential estimator and the combination of ratio exponential estimator and product exponential estimator on systematic random sampling, which is a review and an expansion correction from the article of Singh, et. al. [Journal of Modern Applied Statistical Methods, 10: 424-435]. Each estimator is a biased estimator and the mean square errors are determined. Estimator with the smallest mean square error is the most efficient estimator. An example is given at the end of the discussion.

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