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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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ANALISIS FENETIK TANAMAN KARET (Hevea brasiliensis (Willd. ex A. Juss) Mull. Arg.) BERDASARKAN PENANDA ISOZIM DI LIMA KABUPATEN SENTRA PERKEBUNAN KARET RIAU Ivo Mayasari; Fitmawati '; Minarni '
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

Many kinds of rubber plants (Hevea brasiliensis (Willd. ex A. Juss) Mull. Arg.)has been cultivated in Riau Province. Phenetic analysis of rubber plants can giveinformation about their relationship. Study to obtain information about the relationshipamong rubber plants which are grown in 5 rubber plantation centers in Riau wasconducted based on isozyme markers. A total of 15 trees had been studied. The sampleswere taken from 5 regencies i.e. Bengkalis, Meranti, Kuantan Singingi, Kampar, andRokan Hulu using an exploration method. Four enzymes (PER, EST, ACP, and AAT)were used for similarity and clustering analysis using NTSys program version 2.02. Theresult of this research showed 19 polymorphic bands, 9 bands from PER, 5 bands fromEST, 2 bands from ACP, and 3 bands from AAT enzyme. The similarity analysis of 15individuals showed that the similarity coefficient ranged from 0.47-1. The clusteringresult showed that all of individuals were grouped at the coefficient of 0.59. Most of thesamples were grouped together based on the band similarity. However, all of samplescollected from Bengkalis, as well as Kuantan Singingi, formed a cluster due to the highband similarity.
ANALISIS KORELASI KARAKTER MORFOLOGI TANAMAN KARET (Hevea brasiliensis (Willd. ex A. Juss) Mull. Arg.) DENGAN PRODUKTIVITASNYA DARI LIMA SENTRA PRODUKSI KARET PROPINSI RIAU M. Adi Zulkifli; Fitmawati '; Dewi Indriyani Roslim
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

Rubber plant (Hevea brasiliensis (Willd. ex A. Juss) Mull. Arg.) is one ofcommercial commodities in Riau Province that distributed at several plantation centerssuch as Bengkalis Regency, Kampar, Kuantan Singingi, Meranti, and Rokan Hulu. Thepropagation of rubber plants in long period of time causes variety in latex production.Nowdays, most of the rubber plantations in Riau Province use unstandardized seedlingthat result in diverse and low latex production. The first way to increate latex productionis to identify the morphological characters related to latex production. This research wasaimed to find out the characters that had correlation with latex productivity level. Thisresearch used exploration method. Samples such branches, leaves, and seeds from 10rubber trees for each regency were collected, hence there were 50 samples wereanalyzed. The sample collection was based on the production level. A total of 66morphological characters were analyzed. Seven out of 66 observed character had acorrelation with latex production i.e. dense branch of tree, dense leaf of tree, dense leafof branch, length petiole of main leaf, length petiole of leaflet, length of leaf, and wideof lamina. These characters can be used to select superior rubber plant.
PENENTUAN KUALITAS BATU BATA MERAH BERDASARKAN KONDUKTIVITAS TERMAL Rika Utari; Sugianto '; Erman Taer
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 compressive strength testing (  ) and thermal conductivity testing (k) havebeen performed on red bricks from the district of Tenayan Raya and Rumbai. Thisresearch using a compression machine, iron, solder, thermometer, styrofoam and itspurpose was to prove the theory of the thermal conductivity having relationship tocompressive strength. The result showed that the highest compressive strength due tothe conventional red brick of Rumbai district is 10.82 x 10 5 N/m 2 and the lowestcompressive strength due to the press red brick of Tenayan Raya district is 3.67 x 10 5N/m 2 . The research results of thermal conductivity showed that the thermal conductivityvalue of the best sample of conventional red brick of Rumbai district is 1.05 J/sm  C andthe thermal conductivity value of the lowest sample of press red brick of Tenayan Rayadistrict is 0.857 J/sm  C . The affecting factor of the quality of red bricks is density. Thedensity of conventional red bricks of Rumbai district for compressive strength andthermal conductivity, are 2486.880 Kg/m 3 and 2200 Kg/m 3 , respectively. Meanwhileaverage density of press red brick of Tenayan Raya district for compressive strength andthermal conductivity are 1696 Kg/m 3 and 2000.5 Kg/m 3 , respectively. Based on theresult there was in relationship between compressive strength and thermal conductivitywhich was discribed by the regression equation Y  2 x 10  7 X  0 . 812
RANCANG BANGUN ALAT PERCOBAAN MOMEN INERSIA DENGAN MENGGUNAKAN TIMER OTOMATIS Hari Rizki Pratama; Riad Syech; Sugianto '
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 designing of an automatic experiment ofmoment of inertia using a self-timer with a variation in radius of a cylinder as an inertialbody. This research was done using an experimental method and especially to design aself-timer calculation tools used in the experiment. The trial results showed that at 0.10m height average time for a cylinder rolling on an inclined plane with a slope of 2.87°for 2 m length could be represented by the regression equation that is y = 0.031x +0.400. Based on the result of the experiment, the coefficient of the moment of inertiaranged from 0.509 to 0.523 with a percentage error ranged from 1.800% to 4.600% andstandard deviation of experimental time measured from 0.011 to 0.034 seconds.
PEMBUATAN KOLEKTOR PELAT DATAR SEBAGAI PEMANAS AIR ENERGI SURYA DENGAN JUMLAH PENUTUP SATU LAPIS DAN DUA LAPIS Dial Hayati; M. Ginting; W. Tambunan
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

A research has conducted on "Fabrication of Flat Plate Collector as a Solar EnergyWater Heater with One and Two Covers”, using the experimental methods. Theexperiments were done by putting two types of solar collector on the area that the solarbeam can falls freely that perpendicularly to the surface of the collectors. Themeasurement were carried out on the intensity of solar radiation coming, hot watertemperature and the lost heat by using equipment of a simple pylheliometer and amercury thermometer. This measurements were done in 60 minutes interval every dayfor 14 days of observation. The results obtained for both types of flat plate collectorsproduced 66 liters of water every day. The two tier covered flat plate collector reachedthe highest temperature of 95 o C, which was higher than its of the single-tier coveredflat plate collector of 84 o C. This result was due to the more layers cover the less heatthat lost through the top surface of the flat plate collector. The highest temperature ofthe hot water that accommodated in the tank was 51 o C for the double layer collector lidand 47° C for the one layer of collector lid.
RANCANGAN ALAT SIKLIK VOLTAMMOGRAM UNTUK APLIKASI PADA PENGUKURAN SEL SUPERKAPASITOR A. A. Yani; E. Taer; R. N. Saputra
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

An instrument has been made to measure the voltage and current of supercapacitor cellusing a cyclic voltammetry technique. This instrument consists of a potentiostat and asignal conditioner. Data processing and analyzing were performed using data acquisitionsystem of a 12-bit serial ADC type ADS 7476. The ADC circuit a does not have a registerthat why it is controlled directly by a microcontroller ATmega8. This circuit was used asanalog data converter of supercapacitor cells into digital data. The output voltage of theamplifier of supercapacitor cell was acquired by the ADC before it was interfaced tomicrocontroller. Data obtained from the ADC was sent by the microcontroller to acomputer with an RS232 serial cable and read using Visual Studio C++. The programsoftware Visual Studio C++ controled the retrieval of data by selecting a microcontrollerand gain amplifier programmable which was appropriate that the received signal dataacquisition system becomes more optimal. The read data was stored in the database andthen visualized in the form of graphs and tables of voltammogram measurement data. Thetests conducted in this study was a testing of microcontroller, a signal conditioning andinstrumentation overall. Prototypes of this instrument were tested on a modified carbonelectrode with a mixture substance of CNTs10%, PANI 15%, PVDF 5%, and 70% ofactivated carbon from cassava. The supercapacitor cell was assembled in the form of coins,which comminuted of ribbon Stailess steel (316L) as a current collector, a 1M H 2 SO 4electrolyte and a carbon composite as a working electrode. The measurement of currentobtained a current in the range of -1mA to 0.993 mA at a voltage between 0 Volt to 0.5Volt from a voltammogram curve. The result obtained was then composed with theinstrument tool of the commercial potentiostat. Error percentage of all measurements was ±6.05%.
ANALISA SIFAT FISIS SENSOR KOIL DATAR DENGAN VARIASI GEOMETRI Roberto, R.; Umar, L.; Setiadi, R. N.
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

Flat coil inductive sensors based on Eddy currents principal could work without directmechanical contact on the object, it could work continuously and reactively to theconductive material. This system is easily influenced by external disturbances. Based oninductance value due to changes in magnetic force lines that occurs between the sensorand conductor material (disturbances material). The system could be used as a detectionof distance translation. The used sensors in this study was a flat coil made of PrintedCircuit Board (PCB) technology with various geometric shapes, such as circle, square,rectangle and octagonal. Distance detection analysis were evaluated using a LCoscillator which was directly connected to a computer that able to transform a massiverange measurement into frequencies. Characteristics of distance detection wasinfluenced by geometry of the flat coil sensors with its highest value of frequency of1.68 MHz for a circular shape, 1.66 MHz for an octagonal shape, 1.52 MHz for ansquare shape, 1.42 MHz for an rectangular shape, respectively with the minimumdistances as far as 5 mm for each shape. The temperature tested as external disturbancescaused change in characteristics of the transfer curve based on drift frequency fordistance detection analysis based on a mathematical formula.
PENGUKURAN TINGKAT PENYERAPAN BUNYI KEPINGAN BATANG KELAPA SAWIT DENGAN MENGGUNAKAN TABUNG IMPEDANSI Septina Sari; Erwin '; Krisman '
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

Research on measuring of levels of sound absorption by a piece of palm trunk wasdone. Sample of palm trunk used in this study was 22 years old and made intorectangular pieces with a size of 23 x 23 cm. The thickness of the samples was varied,namely 6mm, 9mm, 15mm. The source of sound used was generated from sweepfunction generator. The sound intensity inside the impedance tube before and afterpenetrating the sample was recorded using sound level meter. The sound frequencyrange used in this research was 100 Hz - 1000 Hz. The results indicated that in general,the sound intensity increases with the increase of sound frequency. However, theintensity of the sound was reduced very significantly after penetrating the sample insidethe tube. For high frequency, namely 1000 Hz then the percentage of sound absorbtionby a piece of trunk palm with the thickness of 6 mm, 9 mm and 15 mm was 3.4 %, 5.7% and 14 % respectively, while, for low frequency, namely 100 Hz, then the percentageof sound absorbtion by the material with the thickness of 6 mm, 9 mm and 15 mm was5.6 %, 8.3 % and 12 % respectively
POTENSI ABU CANGKANG KERANG DARAH (Anadara Granosa) SEBAGAI ADSORBEN ION TIMAH PUTIH G. Afranita; S. Anita; T. A. Hanifah
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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The waste of blood clam seashells (Anadara granosa) can be used as adsorbent of tin.Blood clam seashells was calcinated at 800 0 C of ±9 hours. Blood clam seashellscontained CaO . The aim of this study was to see potential of blood clam seashell ash asabsorbent of tin. The research was conducted by contacting was tin ion and blood clamseashell ash with the variation of concentration. Tin analysis performed by using atomicabsorption spectroscopy (AAS). The results showed that optimal absorption occurs at30 mg/L, at 15 hours was 66,53%.
SINTESIS DAN UJI TOKSISITAS SENYAWA ANALOG 3’, 4’-DIMETOKSI KALKON Novianti, S.; Balatif, N.; Zamri, A.
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

Chalcones belong to important class of flavonoid compounds. They have also beenreported to have anticancer, antimicrobial, antifungal, antioxidant, and cytotoxicactivities. In this research, an analogous chalcone of (E)-3-(4-clorophenyl)-1-(3’,4’-dimetoxyphenyl) prop- 2-en-1-on was synthesized using microwave iradiation andnatrium hidroxide as catalyst. The compound showed a good yield, and then wascharacterized by UV spectroscopy, IR, 1 H-NMR, and Mass Spectroscopy. Its toxicityhas been identified using Brine Shrimp Lethality Test (BSLT) method on Artemiasalina Leach. The result showed that it had a good toxicity activity withLC 50 = 2.24 μg/ mL and potential as anticancer.

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