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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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RESPONS ANAKAN TUMBUHAN NYAMPLUNG (Calophyllum inophyllum L.) PADA BERBAGAI PERIODE PENGGENANGAN Asma Sari; Siti Fatonah; Dyah Iriani
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

Nyamplung (Calophyllum inophyllum L.) is a plant that has many functions, almost all parts of the plant can be used and have high economical and ecological functions.The purpose of this study were to test the growth ability of nyamplung at various periods of flooding and observe the morphological adaptations due to this treatments.This research was carried out for 30 days using a randomized block design (RBD) with a single factor, i.e. period of flooding which consisted of 4 treatments as follow P0: control (no flooding), P1 5 days of flooding periods, P2 10 days of flooding periods, and P3 continuous floding. The flood height from the soil was 2 cm. The results of this study indicated that the flooding periods did not significantly affect the plant fresh weight, the plant height as well as the number of leaves.The flooding periods significantly affected the percentage of root growth and root fresh weight. The morphological adaptation of Nyamplung in the period of flooding was by forming lenticels.While the seedling on continuously flooding treatment also formed adventitious roots. The 4 month nyamplung seedling could grow at all of the flooding periods with injury index at 5, 10 day flooding periods and continuously flooding period were 0, 0.09 and 0.58, respectively.
ANALISIS SPEKTRUM SUARA MANUSIA BERDASARKAN JENIS KELAMIN (GENDER) DAN KELOMPOK UMUR MENGGUNAKAN KOMPUTER Widia Rahim; Erwin '; Usman Malik
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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Research on analysis of human voice spectrum based on gender and age group has been conducted. To record the human voice, it was used a microphone and a computer equipped with a software  called “Praat” as a substitute for spectrum analyzer. From the voice spectra, it was obtained the fundamental frequency (pitch) and formant. The sample of the human voice was recorded based on the male and women  voice which divided  into age group  such as  children aged 8-11 years, adult 19-23 years and elderly aged above 50 years. In this research, it was used 3 pieces of said, namely “Universitas Riau”, “Selamat Datang” and “Mari Berjuang”. The result of this research indicated that pitch of male was lower than that of women. In general,  the relationship between pitch and age showed that the pitch decreases as the age increases.  For male, the pitch decreases very significantly from 245,8 Hz to 124,6 Hz as the age increases from children to elderly, while for women the decrease of pitch was linear with small slope. The average formant value for boys is a little bit higher than that of girls which is 525 Hz and 512 Hz respectively. In general, the value of first formant (F1) decreases as the age of human increases.
DESAIN PEMBUATAN DAN UJI COBA KUMPARAN HELMHOLTZ BERBENTUK LINGKARAN Ginisa Ardiyani; Erwin '; Salomo '
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

Design and study  of Helmholtz coils have been carried out.  The coils  diameter was designed of about    13 cm and  number of turns of    50, 100, 150, 200 and 250. Magnetic field that produced by those coils was measured using  pasco  magnetic probe PS-2162 as a function of an applied current, distances and number of turns. As comparison,  then the magnetic field produced by these coils had been compared to the standard one.  Maximum value of magnetic field was obtained at the center of the coil. For an applied current of 2 A, then the magnetic field at the center of the coils either  standard one  or the designed one  was  7.156 x 10-5T  and 5.907  x 10-5T respectively. The value of magnetic field increases as number of turns and current are increased, for the coils with number of turns of 50 and 250 that carrying current of 1.0 A  produced a magnetic field of  5.241 x 10-5T and 6.208 x 10-5T respectively. This is due to the direct relationship between current (I) and number of turns (N) against magnetic field as expected. The value of magnetic field decreases as moving away from the center of coil either in horizontal or vertical direction.
ISOLASI DNA TANAMAN PADI (Oryza sativa L.) ASAL KECAMATAN BANTAN, BENGKALIS – RIAU. Dita Deanesia; Dewi Indriyani Roslim; Herman '
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

Excess  of  Fe  in  costal  land  in  Riau Province  is potential to  poison the  roots  of  plants. However,the plants have their  own  mechanism  to overcome  the Fe overload.  This  study was aimed  to  isolate  the total   DNAof rice plants among  three  local  rice genotypes  from Riau  which are  commonly  planted in costal  land  in  Bengkalis,  Riau, with  Fe overload resistant  swamp  rice variety  (Mahsuri)  and Fe overload sensitive rice variety  (IR64). The experiment was conducted  in the Laboratory of Genetics, FMIPA UR,from January to May   2014. Research methods  consisted of  isolation  of DNA  and  electrophoresis.  In this study  isolation of DNA  from five rice  varieties  was succesfully done. Among those DNA, concentration  of  total DNA  which were  obtained from IR64 and Amat Candu were very high.
METODE MODIFIKASI NEWTON √ DENGAN ORDE KONVERGENSI 1 + 2 Lely Jusnita; Supriadi Putra; Zulkarnain '
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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We discuss the modification of Newton’s method, which is a Predictor and Corrector method, to solve a nonlinear equation. Using a series based on the equation √ error of the method, we show that the order of convergence of the method is 1 + 2 and for each iteration, it requires two function evaluations, so the efficiency index of the method is 2.4142. To see the advantages of the proposed method, we compare the method with some known iterative methods using four test functions by varying an initial guess.
PEMANFAATAN LIMBAH AMPAS TEBU SEBAGAI ADSORBEN UNTUK PENINGKATAN KUALITAS AIR GAMBUT Patricia Lucky Yoseva; Akmal Muchtar; Halida Sophia
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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Sugarcane bagasse contains various biomass compounds, like cellulose and lignin,which has the potential to be converted into a source of carbon for the adsorption process. This study was aimed to use carbonized bagasse powder as an adsorbent toincrease quality of peat water. Bagasse powder was carbonizied at 300 o C for 2,5 hoursand sieved using a sieve storied 100 and 200 mesh. Carbonizied bagasse powder wascharacterize in terms of moisture content, ash content, I 2 adsorption capacity, surfacearea and functional groups determination using FTIR. Adsorption process was observedby mass variations (0,5; 1; 1, 5; 2 grams) then at the mass maximum (2 gram) wascontinued by contact time variations (30, 60, 90, 120 minutes). Parameters of this studywere analyzed such as odor, colour, pH, turbidity, TDS, TSS, metal content of Fe andhumic acid in peat water. All of the results were compared to PERMENKES RI “AboutRequirement and Water Quality Control” No.416/MENKES/PER/IX/1990. The analysisresult showed that variation of contact time does not affect all parameters that have beenanalyzed. After compared to PERMENKES RI only odor, turbidity, TDS, content of Fe(2 grams; 120 minutes) fulfilled the standar, respectively (18,2 NTU; 54,15%),(98 mg/L; 52,65%), and (0,128 mg/L; 52,65%).
OPTIMALISASI pH PRODUKSI SELULASE DARI BAKTERI ENDOFITIK Pseudomonas stutzeri LBKURCC53, Pseudomonas stutzeri LBKURCC54, dan Actinobacter antratus LBKURCC60 Rizki Wulandari; Silvera Devi; Andi Dahliaty
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

Cellulase is an enzyme that can hydrolyze the β-1,4 bonds on cellulose and productionof glucose so that the enzyme is widely used in various industries. Cellulose enzymes can be produced by microorganism such as endophytic bacteria (LBKURCC53, LBKURCC54, and LBKURCC60). The activity of cellulase enzyme was determined by measuring the glucose produced using Nelson-Somogyi method. The optimum activity of cellulase enzyme from theisolates of LBKURCC53, LBKURCC54, and LBKURCC60 we measured at different pH. The enzyme of LBKURCC53 isolate was optimum at pH 7 with enzyme activity of 11,31 ± 1,69 x 10 -3 U/mL. While the enzyme of LBKURCC54 and LBKURCC60 isolates were optimum at pH 6,5 with enzyme activity 14,44 ± 2,94 x 10 -3 U/mL and 8,33 ± 1,11 x 10 -3 U/mL respectively. These comparison of cellulase enzyme activity of isolates LBKURCC53, LBKURCC54, and LBKURCC60 were determined by using Duncan multiple range test at 5% level (α≥0,05).
ANALISA PENGARUH VEGETASI TERHADAP TINGKAT KEBISINGAN DI SEPANJANG JALAN RAYA PEKANBARU-BANGKINANG Azura '; Erwin '; Defrianto '
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

The influence of vegetation such as ketapang, sengon, mango, of acacia, durian andpalm along Pekanbaru-Bangkinang highway against noise level has been studied. Noisesource was originated from sound of vehicles passing through the highway. An instrument used to record the noise level in the study is Sound Level Meter (SLM). In order to obtain the absoption of noise level, then it was used 2 SLMs. The first SLMwas utilized to record the noise directly generated by vehicles without any obstaclesand the second SLM was located behind the trees as sound obstacles. The position ofthose two SLMs was arranged along the road with the distance of about 15 m from thehighway. The next measurement was to record the noise level for one day started from7: 00 a.m until 6: 00 p.m along the highway. The influence of the distance against thenoise level was also studied. The result of this research showed that palm trees has thehighest effect on noise reduction and followed by acacia, mango, durian, sengon andketapang trees. The high absorption of sound by palm tree of about 6.092% because the volume of the palm leaves per percentage of the absorption is smaller compared tothose for other vegetations. These results were compared to those of Maekawa andISO9613 calculation. From the comparison, it was obtained that Maekawa calculation ishigher compared to those of this research, while the ISO9613 calculation was lower.The error percentage of the calculation for Maekawa and ISO9613 was 6.82% and8.76% respectively. The profile of one day noise along the highway as a function of time showed that there were two peaks of noise that were occurred at 09.00-10.00 and17.00-18.00. Moreover, the noise level was reduced very significantly from 71.90dB(A) to 63.58 dB(A) as the measurement away from the noise source.
ANALISA PENGARUH KEBERADAAN BANGUNAN TERHADAP TINGKAT KEBISINGAN DI SEPANJANG JALAN RAYA PEKANBARU-BANGKINANG Sandra Septiana; Erwin, '; Defrianto '
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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The influence of the existence of buildings as a barrier on the noiselevel alongPekanbaru-Bangkinang highway had been studied. A source of noise in this researchwas generated by vechicles passing through along the highway. A tool used to record the noise level was Sound Level Meter (SLM). There were two SLMs used in this measurement, where the first SLM wassituated in the back of the building and thesecond SLM waslocated parallel to the first SLM along the highway without anybuildings.There were four types of buildings used as a noise barrier namely buildingmade of concrete, briks, semi-permanent, and wood. The resultsof the measurementshowed that thehighest noise absorption of about 18.15 %was due to the buildingmade from concrete and followed by bricks, semi-permanent, and woodtheir absorptionvalue of 14.36 %, 13.60 %, and 12.15 % respectively. The highestvalue of absorption ofnoise by concrete building was due to small space volume per percentage of noiseabsorption compared to those of other buildings. The results of this research werecompared to those of Maekawa and ISO9613. The noise absorption in this research wasa little bit lower compared to Maekawa calculation and higher than those for ISO9613with the average error percentage of about 3.35 % and 10.56 % respectively. Themeasurement of noise level as a function of time for one day started from 07.00-18.00showed that the noise level profile had two peaks that was at 12.00-13.00 and 16.00-18.00 with the value respectively of 68.89 dBA and 69.20 dBA. The valueof the noiselevel were also studied as a function of distance and its value declinedverysignificantlyfrom 71.07 dBA to 61.47 dBA when the measurement away from the noisesource.
KARAKTERISTIK MORFOMETRIK DAN MERISTIK IKAN LAIS DANAU (Ompok hypophthalmus Bleeker, 1846) DI SUNGAI TAPUNG DAN SUNGAI SIAK Putri, Riri Anggraini; Elvyra, Roza; ', Yusfiati
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

This research is one of study about morphometric-meristic of lais danau fish (Ompokhypophthalmus) in two different habitats, Tapung river and Siak river. The purpose of this research is to determine the difference between morphometric and meristic of male lais danau fish and female lais danau fish in Tapung river and Siak river. This research was conducted on January-March 2014. As many as 60 fish (consisting of 30 males and 30 females) were collected every month for each loacation. The data were analyzed using Microsoft Excel and SPSS Version 16. Morphometric characters of lais danau fish in Siak river, are smaller than the males and females of lais danau fish in Tapung river. The growth status of lais danau fish for each location of the research are positive allometric, negative allometric, and isometric. T-test showed that morphometric between male lais danau fish and female lais danau fish for each location of the research were significant different. Meristic of male lais danau fish and female lais danau fish for each location of the research were not significant different.

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