Browsing by Author "Martina"

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    Study of Performance of the Electric Generator Portable With NaCl Concentration Variation
    (2016-04-22) Amri, Idral; Sahan, Yusnimar; Martina; Sari, Jenita Maya
    In Indonesia, the consumption of fossil oil as an energy resource will be reduced from 52% in 2015 to 20% in 2025. Galvani cell is one of many energies alternative, and it can be used as an electric resources. In this research, the portable electric generator was designed and builds to generate electric. This generator consists of magnesium AZ91 as an anode, the metal cell MAB5A as a cathode, and NaCl solution as an electrolyte. The objective of this research is determine the performance of this generator by using NaCl concentration variation 6%, 7%, 8%, 9% and 10% and amount of the electrodes pair. The performance of this equipment was measured with a multi tester and Light Emitting Diode (LED) bulb. Results, LED bulb was light on for 31 hours by using NaCl 10% and 10 electrodes pair, this generator unit produced the electric voltage 15.47 volt.
  • No Thumbnail Available
    Item
    A Study On The Ability Of The Second Year Students Of Sma An-Naas Pekanbaru In Writing Explanation Text
    (2012-11-07) Martina
    A STUDY ON THE ABILITY OF THE SECOND YEAR STUDENTS OF SMA AN-NAAS PEKANBARU IN WRITING EXPLANATION TEXT MARTINA Student of English Language Education Department Faculty of Teacher’s Training and Education Riau University Abstract The purpose of this research is to know how good is the ability of the second year students of SMA An-Naas Pekanbaru in writing explanation text. The subjects were 20 students from XI science class at SMA An-Naas Pekanbaru. The researcher used the writing test as an instrument in collecting the data. The students’ score were analyzed by three raters. The aspects which were evaluated were; grammar, vocabulary, mechanic, fluency and organization. The results showed that the most difficult aspect of writing for students is grammar, where the average score was 69.5. Then, the students’ highest score was in the aspect of organization, with the average score of 81.9. Based on the assessment of each aspect of writing, the students who got 80-100 are 3 students(15%), it belongs to good to excellent level. Then, the students who got 60-79 are 17 students (85%) which belongs to average to good level. Finally, the researcher gets the conclusion that the percentage of students’ ability in writing explanation text is in the average to good level.