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Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam
Published by Universitas Riau
ISSN : -     EISSN : -     DOI : -
Core Subject : Education,
Mathematics
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Articles 424 Documents
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KONKURENSI TITIK GERGONNE Desi Trisna; M. Natsir; Hasriati '
Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam Vol 1, No 1 (2014): Wisuda Februari 2014
Publisher : Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam

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Abstract

This paper discusses the proof of the concurrent from Gergonne point. The Gergonnepoint of a triangle is the point at which the three lines from vertices to the points oftangency between the incircle and the sides of the triangle are concurrent. ConcurrentGergonne point can be proved through several methods and using Ceva theorem. Theconcurrence of Gergonne point is also proved on excircle of triangle.
PENAKSIR RATIO-CUM-PRODUCT YANG EFISIEN UNTUK RATA-RATA POPULASI PADA SAMPLING ACAK SEDERHANA MENGGUNAKAN KOEFISIEN VARIASI DAN KOEFISIEN KURTOSIS Liza Yarmanita; Arisman Adnan; Firdaus '
Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam Vol 1, No 1 (2014): Wisuda Februari 2014
Publisher : Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam

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Abstract

This article reviews three ratio-cum-product estimators for the population mean insimple random sampling. The coefficient of variation and the coefficient of kurtosis ofauxiliary variables are used. This article is the review of Tailor’s et. al. Article[Communications of the Korean Statistical Society 18(2):155-164]. The estimatorsdiscussed are ratio-cum-product estimator, type 1 and type 2 ratio-cum-productestimators using coefficient of variation and coefficient of kurtosis. These estimators arebiased. Then, the mean square errors (MSE) of each estimator are compared to showwhich one is the most efficient estimator. The type 2 ratio-cum-product estimator usingthe information on coefficient of variation and coefficient of kurtosis is the mostefficient estimator among the other two estimators.
ISOTOMIK KONJUGAT DARI TITIK GERGONNE DAN TITIK NAGEL Martha Sri P.; M. Natsir; Hasriati '
Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam Vol 1, No 1 (2014): Wisuda Februari 2014
Publisher : Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam

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Abstract

This paper discusses an isotomic conjugate from Gergonne point and Nagel point,which are the point of concurrence formed by connecting the vertices of a triangle withthe tangent point of incircle of the triangle and the tangent point of excircle of thetriangle. It also discusses the area of the triangle formed by the isotomic lines andCartesian coordinates from Gergonne point and Nagel point.
TOTAL FENOLIK,FLAVONOID SERTA AKTIVITAS ANTIOKSIDAN EKSTRAK n-HEKSANA, DIKLOROMETAN DAN METANOL Amaranthus spinosus L EM5-BAWANG PUTIH Yondra Arif D; Christine Christine Jose; Hilwan Yuda Teruna
Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam Vol 1, No 2 (2014): Wisuda Oktober 2014
Publisher : Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam

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Abstract

The objective of this study was to analyze the total phenolics, total flavonoids, and antioxidant activities of Amaranthus spinosus L leaves. During cultivation, these plants were treated with 2 treatments, biocontrol Effective Microorganism 5 (EM5) garlic and control (water). The A. spinosus L leaves were dried using freeze dryer and extracted by dissolving n-hexane, dicloromethane (DCM) and methanol. The results showed that A.spinosus L leaves treated with biocontrol had the highest total phenolic, total flavonoid and antioxidant activity content compare to the control. The total phenolic, total flavonoid, 2,2 diphenyl-1-picrylhydrazyl (DPPH) and Nitric Oxide (NO) radical scavenging were the highest on DCM extract with each value of 74,656 mg Gallic Acid Equivalent (GAE)/g of dry weight (DW), 22,337 mg Catechin Equivalent (CE)/g DW, 0,373 mg/mL and 0,025 mg/mL. n-Hexane extract had the highest antioxidant activity on Ferric Thiocyanate (FTC) test (27,615 %), meanwhile methanol extract indicated the highest antioxidant activity on FRAP test (1,022 mmol Fe+2/g DW). From this study, it can be concluded that A. spinosus L leaves with biocontrol Effective Microorganism 5 (EM5) garlic can increase the phenolic, flavonoids and antioxidant activitiy contents of A. spinosus L plant.
ANALISIS RUGI- RUGI DAYA PADA PENGHANTAR SALURAN TRANSMISI TEGANGAN TINGGI 150 KV DARI GARDU INDUK KOTO PANJANG KE GARDU INDUK GARUDA SAKTI PEKANBARU Muhammad Radil; Riad Syech; Sugianto s
Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam Vol 1, No 2 (2014): Wisuda Oktober 2014
Publisher : Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam

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Abstract

A research has been conducted on analysis of power losses on electric power transmission line of 150 kV of Koto Panjang to Garuda Sakti Pekanbaru in March 2014. This research was conducted and its aim was to analyze the power losses in the transmission system 150 kV. Conductors used in the high-voltage transmission line wasACSR (Aluminium Conductor Steel Reinforced) which consisted of a mixture of aluminum and steel with a diameter of 28.71 mm. Results of the transmission lineshowed that the largest total conductivity obtained was 43,645,705.993 Watt at 13:00 PM while the lowest total conductivity was 37,313,100.282 Watt at 17:00 PM. Highermagnitude of the transmitted conductivity resulted in increased power loss with ACSRconductor resistance of 0.049 Ω so that the largest loss occurred at 13:00 PM with4435.645 Watt power loss and the lowest power loss was 3,221.784 Watt at 17:00 PM.Based on the results obtained above, the percentages of power lost every hour for amonth in March 2014, were between 0.0086% to 0.0102% with the percentage ofoverall average power loss was 0.095%. 
PENGOLAHAN AIR GAMBUT DENGAN KOAGULAN CAIR HASIL EKSTRAKSI LEMPUNG ALAM DESA CENGAR MENGGUNAKAN LARUTAN H 2 SO 4 Sutrisno, Hevi; ', Muhdarina; Amri, T. Ariful
Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam Vol 1, No 2 (2014): Wisuda Oktober 2014
Publisher : Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam

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Abstract

Liquid coagulant from Cengar clay was used for peat water treatment. The steps forproducing liquid coagulant were clay calcination at 500 o C for 3 hours and extraction by0.2 mol H 2 SO 4 solution with variation of temperature (30, 60, 100 o C) and time (1, 2, 3hours). The coagulants were tested for peat water coagulation by measuring pH,turbidity, and TDS. The results were compared to PERMENKES No.416/MENKES/PER/IX/1990 “Tentang Syarat-syarat dan Pengawasan Kualitas Air”. After coagulation,the parameters of peat water were improved. The pH value of peat water aftercoagulation was between 5.0-8.5, turbidity 2.0-6.5 NTU, and TDS 250-320 mg/L.Compared to No.416/MENKES/PER/IX/1990, turbidity and TDS from all samples aftercoagulation have met the water quality standard. The best coagulant was K 100-2 with thevalue of the parameters after coagulation were 8.39 of pH, 4.75 NTU of turbidity and258 mg/L of TDS. According to the results, it can be concluded that liquid coagulantfrom Cengar clay can be used for peat water treatment.
PEMEKATAN ENZIM SELULASE Penicillium sp. LBKURCC20 DENGAN PENGENDAPAN AMONIUM SULFAT 80% JENUH Masdalena Sinaga; Titania T. Nugroho; Andi Dahliaty
Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam Vol 1, No 2 (2014): Wisuda Oktober 2014
Publisher : Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam

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Abstract

Cellulase enzyme activity of Penicillium sp. LBKURCC20 Isolate of Riau can beincreased by concentrating the enzyme using 80% saturated solid ammonium sulfate(NH 4 ) 2 SO 4 anhydrous. Precipitated enzyme was redissolved by the addition of acetatebuffer solution pH 5.5 to 1/70 times its original volume. Cellulase enzyme activity wasdetermined using substrates CMC and avicel. CMCase and avicelase enzyme activity ofthe crude enzyme was (0.0164 ± 0.0036) U/mL and (0.003 ± 0.0025) U/mL,respectively. CMCase and avicelase enzyme activity after concentration was (0.219 ±0.0579) U/mL and (0.03 ± 0.03) U/mL, respectively. The test results showed that theactivity of concentrated CMCase increased 13.5 times and avicelase enzyme activityincreased 10 times after concentrating.
SINTESIS DAN UJI AKTIVITAS ANTIBAKTERI DARI SENYAWA 1-FENIL-3-(1-NAFTIL)-5-(2-KLOROFENIL)-2-PIRAZOLIN Dahliarti '; Hilwan Yuda Teruna; Jasril '
Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam Vol 1, No 2 (2014): Wisuda Oktober 2014
Publisher : Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam

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Abstract

Pyrazoline is a bioactive compound but it is rare in nature. Pyrazoline has bioactivitieswhich are anti-inflammantory, antimicrobial, antibacterial, antidiabetic and antipyreticactivity. In this study this compound has been synthesized by reacting phenylhydrazinewith (E)-3-(2-chlorophenyl)-1-(naphtalen-1-yl)prop-2-en-1-one chalcone and thencatalyzed by acetic acid using microwave irradiation method. The yield of 1-phenyl-3-(1-naphtyl)-5-(2-chlorophenyl)-2-pyrazoline compound was 76,23%. This pyrazolinewas characterized using UV-Vis, IR, 1 H-NMR and 13 C-NMR spectrometer. Bioactivitytest showed that the pyrazoline compound does not have antibacterial activity againtGram-positive and Gram-negative bacteria.
PENGARUH KONSENTRASI REAKTAN TERHADAP KONVERSI LIMBAH PELEPAH SAWIT MENJADI ASAM LEVULINAT DENGAN METODE HIDROLISIS MENGGUNAKAN KATALIS ASAM SULFAT Arif Kurnia; Amir Awaluddin; Edy Saputra
Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam Vol 1, No 2 (2014): Wisuda Oktober 2014
Publisher : Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam

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Abstract

Palm frond could be hydrolyzed to levulinic acid using acid catalyst. In this study,kinetics data and optimum condition of palm frond conversion to levulinic acid wasinvestigated. The conversion was conducted in ampoule as reactor (length of 150 mm,I.D. of 4 mm and O.D. of 7 mm) over the following range of condition: palm frondconcentrations of 1-5 wt% (1-5 g/100 mL), temperature of 190 o C, sulfuric acidconcentrations of 1 M, and residence times of 0-240 min. The maximum LA yield isapproximately 9,38% (based on biomass weight) and 31,28% (based on celluloseweight) was achieved for an initial palm frond concentration of 1 wt% (w/v), acidconcentration of 1 M, temperature of 190 o C, and residence time of 60 min. The resultshowed that the concentration and yield of levulinic acid was affected by palm frondconcentration, but didn’t affect reaction rate.
TOTAL FENOLIK,FLAVONOID SERTA AKTIVITAS ANTIOKSIDAN EKSTRAK n-HEKSANA, DIKLOROMETAN DAN METANOL Amaranthus spinosus L EM5-BAWANG PUTIH Yondra Arif D; Christine Jose; Hilwan Yuda Teruna
Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam Vol 1, No 2 (2014): Wisuda Oktober 2014
Publisher : Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam

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Abstract

The objective of this study was to analyze the total phenolics, total flavonoids, andantioxidant activities of Amaranthus spinosus L leaves. During cultivation, these plantswere treated with 2 treatments, biocontrol Effective Microorganism 5 (EM5) garlic andcontrol (water). The A. spinosus L leaves were dried using freeze dryer and extracted bydissolving n-hexane, dicloromethane (DCM) and methanol. The results showed thatA.spinosus L leaves treated with biocontrol had the highest total phenolic, totalflavonoid and antioxidant activity content compare to the control. The total phenolic,total flavonoid, 2,2 diphenyl-1-picrylhydrazyl (DPPH) and Nitric Oxide (NO) radicalscavenging were the highest on DCM extract with each value of 74,656 mg Gallic AcidEquivalent (GAE)/g of dry weight (DW), 22,337 mg Catechin Equivalent (CE)/g DW,0,373 mg/mL and 0,025 mg/mL. n-Hexane extract had the highest antioxidant activityon Ferric Thiocyanate ( FTC) test (27,615 %), meanwhile methanol extract indicated thehighest antioxidant activity on FRAP test (1,022 mmol Fe +2 /g DW). From this study,it can be concluded that A. spinosus L leaves with biocontrol EffectiveMicroorganism 5 (EM5) garlic can increase the phenolic, flavonoids and antioxidantactivitiy contents of A. spinosus L plant.

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