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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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MATRIKS REFLEKSIF TERGENERALISASI Hendra Maryulis; Sri Gemawati; Asli Sirait
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

In this article we discusses a generalized reflexive matrix A that has a relation PAQ A  and , PAQ A   , m n C A   where , n n C P   and m m C Q   are two generalized reflection  matrices. The  discussion was continued by discussing the properties of generalized reflexive matrix, namely orthogonal-L, orthogonal-R and the linear least squares problems whose coefficient matrix is of the form a generalized reflexive matrix.
KARAKTER MORFOLOGI UBI KAYU (Manihot esculenta Crantz) HIJAU DARI KABUPATEN PELALAWAN Rini Restiani; 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

Many cassava varieties or genotypes have been grown or planted by farmer in Pelalawan, and one of them is cassava cv. Hijau. This study was aimed to identify morphological character of cassava cv. Hijau from Pelalawan. The cassava stems were obtained from Langgam, Kabupaten Pelalawan. The seven cassava stems were planted as replication. Morphological characters, including leaf shape, color of apical and fifth leaf, petiole color, stem color, stem diameter, flower, fruit, and tuber, were observed on 5 and 12 months after planted. Results showed that cassava cv. Hijau had lanceolate leaf with sharp tip, light-green apical leaf, and dark-green fifth leaf. The petiole was yellowish-green. The stem diameter was medium (12-25 mm) and the color stem was yellowish-green. The flower was monoecious. The fruit was rounded and jagged. The tuber shape was cylindrical and its color was white.
TOTAL FENOLIK, FLAVONOID, DAN AKTIVITAS ANTIOKSIDAN PRODUK TEH HIJAU DAN TEH HITAM TANAMAN BANGUN-BANGUN (Coleus amboinicus) DENGAN PERLAKUAN ETT REMPAH-REMPAH Restauli Br Siburian; Christine Jose; Ganis Fia Kartika
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 a plant with good antioxidant content . Antioxidants are very important  in preventing various diseases caused by free radicals.   The high antioxidant content of plant  C. amboinicus  potentially  used as raw material for making herbal tea products, such as  green tea and black tea. The objective of this research was to analyze the  total phenolics, flavonoids and antioxidant activity of green tea and black tea prepared from  C. amboinicus  plants with two different treatment, fermented plant extract (FPE) spice and control (water).  The results showed that the total phenolic and flavonoid content  of each  treatment  was different. The total phenolic content of control treatment and FPE spice green tea and black tea products  were  16,660 ± 0.251 mg AGE/g DW; 10.510 ± 0.737 mg AGE/g DW and 14,219 ± 0,198 mg AGE/g DW; 8.062 ± 0.334 mg AGE / g DW. Were  the total flavonoids treatment control and FPE spice green tea and black tea is 3.522 ± 0.077 mg CTE/g DW; 2.141 ± 0.104  mg CTE/g DW and 2.278 ± 0.057 mg CTE/g DW; 2.077 ± 0.044 mg CTE/g DW.  The content  of antioxidant activity by FTC method is highest shown  in the control treatme nt compared with ETT RR good green tea products and  black tea.  It can be concluded that green tea product of  C. amboinicus  is better  source of flavonoids, phenolics and antioxidant activity compared with the black tea product.
RESPON KECAMBAH PADI (Oryza sativa L.) SOLOK TERHADAP CEKAMAN GARAM Rahmi Anandia; 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

The salt-stress tolerant rice genotypes are very important to overcome the salt stress in coastal area. This study was aimed to analyze the responses of shoot and root of rice seedlings to the salt stress. The rice genotype (Solok) tested was originally from Kecamatan Bantan, Kabupaten Bengkalis. This study was conducted using Randomized Block Design with three replications. The rice was treated with different salt concentrations, i.e 0 mM (control), 15 mM, 30 mM, and 45 mM. The results showed that the root growth and biomass of Solok genotype was not significantly different between various treatments. This happened because the salt concentration was low. Similarly with the root growth and biomass, the shoot growth and biomass of Solok genotype was not significantly different between various treatments of the salt-stress.
PEMANFAATAN LEMPUNG DESA GEMA TERAKTIVASI H2SO4 UNTUK PENINGKATAN MUTU MINYAK GORENG CURAH Simanjuntak, Martha Sari; Muchtar, Akmal; Sophia, Halida
Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam Vol 2, No 1 (2015): Wisuda Februari 2015
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Abstract

Clay from Gema Village, Kampar Regency, Riau Province has been applied as an adsorbent. The increase of clay’s adsortive capacity can be done by modification. This study was aimed to use the activated clay to improve the quality of bulk cooking oil. The adsorbent preparation was began with activation process by using 0,5 M H2SO4, for 3 hours, and stirring rate 500 rpm. Activated clay showed the increase the intensity of quartz and montmorillonit, and accompanied by the loss of muscovite and kaolinite. The parameters that were used in this study were peroxide value, acid value, water content, odor, and colour. Adsorption process was observed in 7 gram activated clay with various contact time (30, 60, 90, and 120 minutes), the results then compared with SNI 3741:2013. The obtained result showed that the activated clay 0,5 M H2SO4 was able to decrease the acid value, and water content, respectively 54,55%, 48,75% with 120 minute and 7 gram weight of activated clay, it was also able to decrease peroxide value 39,64% with 60 minute and 7 gram weight of activated clay, and the color of bulk cooking oil was more clear, but it’s smells like clay.
POLA PERGERAKAN DAN WILAYAH JELAJAH GAJAH SUMATRA (Elephas maximus sumatranus) DENGAN MENGGUNAKAN GPS RADIO COLLAR DI SEBELAH UTARA TAMAN NASIONAL TESSO NILO, RIAU Erwanda Trio Bintan Sabri; Haris Gunawan; Khairijon '
Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam Vol 1, No 2 (2014): Wisuda Oktober 2014
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Abstract

The Sumatran Elephant is one of the largest land mammal species that exist on the island of Sumatra which is currently critically endangered. The main threat for Sumatran elephant conservation is the fragmentations of its habitat which have been causing a conflict between elephants and humans. Tesso Nilo National Park is an area used as the original habitat of the Sumatran elephants which has now undergone encroachment. Conflicts between humans and elephants have become a much-talked-about issue and a factor which cause the depletion of population of the Sumatran elephant. This research aimed to determine the pattern of movement and the use of space by Sumatran elephants in the habitat that has experienced disturbance by human using GPS Collar and GIS technologies. The data of this research was acquired by attaching a GPS Collar on the leader of the elephant clan and processed using excel and arcGis program. This research was conducted from January 2013 to January 2014 in the northern part of Tesso Nilo National Park (TNTN). The results showed that the daily movement pattern of the elephant was random with an area of 56.631 ha and through several different land types. The elephant preferred a land type with more dense canopy and less disturbance.
PEMANFAATAN LEMPUNG DESA GEMA TERAKTIVASI H 2SO 4 UNTUK PENINGKATAN KUALITAS AIR GAMBUT Vina Rotua; 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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Abstract

The clay found in Gema  Village, Kampar  Regency, Riau  Province  contains  many minerals, such as montmorillonite but it has a low surface area so need to do activation. The activator used in this study was  H2SO4 0,5 M solution. The adsorbent  was characterized by XRD, SEM and FT-IR. Activated Gema clay (LGT) and  unactivated Gema clay (LGTT) were applied for  purification a  peat water  using batch method with the  variation of  time 30, 60, 90 and 120 minute  and  several of water parameters were analized, such as odor, colour, pH, turbidity, TSS, TDS, concentrations of iron (Fe) and efficiency  of decreasing  of  colour. All the results  were compared  to  PERMENKES RI No. 416/MENKES/PER/IX/1990 “Tentang Syarat-Syarat Dan Pengawasan Kualitas Air”.  Activated  clay  showed the  refined morfology and increased which  surface area from 10,5813  m2g-1 up to 15,3337  m2g-1.  The  result  showed  that the  adsorption  using activated Gema clay is better than  unactivated Gema clay  that is showed from removal efficiency percentage for all parameters. The longer  of adsorption time, that was so many adsorbate that was adsorbed by adsorbent.  The maximum time  of  adsorption  was 120 minute. The  removal efficiency percentage  for pH, turbidity, TSS, TDS and efficiency of decreasing  of  colour were 10,03%, 30,98%, 58,59%, 59,28% and 30,84%, respectively for activated Gema clay (LGT).  The statistic result showed that the variation of adsorption time affect all parameters that  was  analyzed based on the analysis of variance (ANOVA) and Duncan’s test at α = 0,05.
DESKRIPSI KARAKTER MORFOLOGI UBI KAYU (Manihot esculenta Crantz) JURAY DARI KABUPATEN ROKAN HULU Murtiana Caniago; Dewi Indriyani Roslim; Herman '
Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam Vol 1, No 2 (2014): Wisuda Oktober 2014
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Abstract

Cassava is an alternative food to substitute rice as a staple food. The improvement of cassava in breeding program requires many high genetic diversity of cassava. The objective of this study was to describe the morphological characters of cassava cv. Juray from Kabupaten Rokan Hulu, Riau. This research was conducted at Biology Department, FMIPA UR, for 12 months, started from March 2013 to February 2014. The cassava stems were planted and then observed on fifth and twelfth months. The results showed that cassava cv. Juray had morphological characters as follows: the stem color was grey, the stem diameter was large (3.4 cm), the stem texture was grooved, the petiole length was medium (9.77), the flowering time was 10 months after planting, the tuber shape was irregular, the external color of tuber was light brown, the tuber cortex thickness was thin (1 mm), the tuber cortex color was cream, and the root pulp color was white.
PEMBUATAN DAN KARAKTERISASI KARBON AKTIF MONOLIT DARI KAYU KARET DENGAN VARIASI KONSENTRASI KOH UNTUK APLIKASI SUPERKAPASITOR Inrizky Domy Muchammadsam; Erman Taer; Rakhmawati Farma
Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam Vol 2, No 1 (2015): Wisuda Februari 2015
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Abstract

Development of monolithic carbon electrodes with a combination of physical and chemical activation  process  can improve  performance of cell supercapacitor.  Monolithic carbon electrodes  were made  from  rubber wood cross-section of the printed form of  pellets, then  were carbonized  at temperature of  600ºC in N2  gas  atmosphere and  followed by physical activation process at 900ºC  for 2 hours in a CO2  gas atmosphere. KOH of  1 and 5 M  and  HNO3  of  25% solutions  were used as  of the chemical activation  in order  to  activate functional groups. Characterization of electrochemical supercapacitor cell utilized  two-electrode  of  cyclic voltammetry with  1 M H2SO4  solution was used as  electrolyte.  Scanning electron microscope and X-ray diffraction were carried out to study  the structure of surface morphology  and  crystalline properties of monolithic carbon electrodes.  Specific  capacitance  for electrodes  1 M KOH and 5 M KOH  was obtained  as high as  71.08 and 115.38 F/g  respectively.  These results indicate that increasing the concentration of KOH can improve the performance of the electrode supercapacitor cells.
UJI EFEKTIVITAS BAKTERI PELARUT FOSFAT PENGHASIL ASAM SIANIDA ASAL TANAH GAMBUT RIAU DALAM MENGENDALIKAN GULMA DOMINAN PADA TANAMAN KELAPA SAWIT Tri Septiani; Delita Zul; Mayta Novaliza Isda
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

This research aimed to analyze the effectiveness of phosphate solubilizing bacteria (PSB) which are able to produce cyanide acid (HCN) in controlling of predominant weed in the palm oil plantation. This research was conducted from February to July 2014 in the Laboratory of Microbiology, Faculty of Mathematics and Natural Science, University of Riau. The effectiveness of PSB in controlling the growth of Mikania micrantha was performed by inoculating 26 selected PSB isolates into pre-germinated weed based on the Kremer and Souissi method modification. The parameters observed were root length and shoot length of seedling weed. The results showed that PSB isolates tested, in general, were effective to inhibit the growth of root and shoot length of the weed. BB_K9 isolate was the most effective in controlling the weed as it had a strong level of HCN production.

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