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Alotrop
Published by Universitas Bengkulu
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Core Subject : Science,
Jurnal Alotrop adalah majalah ilmiah resmi yang diterbitkan oleh Program Studi Pendidikan Kimia Jurusan Pendidikan MIPA Fakultas Keguruan dan Ilmu Pendidikan Universitas Bengkulu, sebagai sumbangannya kepada pengembangan Ilmu Kimia dan Pendidikan Kimia yang diterbitkan dalam Bahasa Indonesia yang memuat hasil-hasil penelitian, telaah/tinjauan pustaka, kasus lapangan atau gagasan dalam bidang ilmu Kimia dan Pendidikan Kimia
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Articles 13 Documents
Search results for , issue " Vol 2, No 2 (2018)" : 13 Documents clear
PERBANDINGAN HASIL BELAJAR MENGGUNAKAN MODEL PEMBELAJARAN KOOPERATIF TIPE STAD DAN CRH PADA MATERI HIDROLISIS GARAM Amida, Nadia; Andromeda, Andromeda; Bahrizal, Bahrizal
Alotrop Vol 2, No 2 (2018)
Publisher : FKIP University of Bengkulu

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Lesson about  hydrolysis  requires students to understand the concepts hydrolyzed from  type of salt which is then applied in the calculation. In  learning process, students direct involvement is necessary, so that it is used a method that can increase the activity of students. Student Teams Achievement Division (STAD) cooperative learning and Course Review Horey (CRH) expected to create learning that has caharacterized as student centered.  This research aims to reveal students' learning outcomes using STAD cooperative learning and CRH on the hydrolisis material in class XI SMAN 8 Padang. This type of research is experimental research using a randomized study design Control Group Posttest-Only Design is expanded. The study population was a class XI IPA SMAN 8 Padang. Giving  a test at the end of the study as many as 25 pieces of matter objectively. Results of tests of normality and homogeneity of the two classes that both classes of samples obtained samples were normally distributed and had homogeneous variance. After being tested on a real level t = 0.05 with degrees of freedom (df) of 59 obtained t of 2.53 while t table of 1.67. From the research shows that the learning outcomes of students with STAD cooperative learning model is significantly higher than the results of student learning with cooperative learning model CRH hydrolysis of salts in the material in class XI of SMAN 8 Padang.
UJI AKTIVITAS ASAP CAIR CANGKANG BUAH KARET (Hevea brassiliensis) DAN APLIKASINYA DALAM PENGHAMBATAN KETENGIKAN DAGING SAPI Putri, Haulia Dwi; Sumpono, Sumpono; Nurhamidah, Nurhamidah
Alotrop Vol 2, No 2 (2018)
Publisher : FKIP University of Bengkulu

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This research was aimed to know the degree of Fenol compound, total acid and the activity of liquid smoke of Rubber (Hevea brassiliensis) Seed Shell also the application in obstructing the rancidity of beef. The Fenol compound was determined by using Reagen Follon-Ciocalteu. The total acid was determined by using the method of titrated acids.The ability as the antioxidant was tested by DPPH method and the ability of obstructing the rancidity of beef was done by measuring the alteration of TBA value in beef as long as saved. The result was shown the fenol compound in liquid smoke of Rubber Seed Shell as much as 0,84 % and the acetic acid content was 4.725%. The antioxidant test was produced IC50 value as much as 101.27 ppm. According to the IC50 value which got from the test that the liquid smoke of Rubber Seed Shell were included in moderate category. The increment of the liquid smoke of Rubber Seed Shell were able to suppress the rancidity of beef during the storage time. It was marked by the decreasing of TBA value in beef as given in treatment A1 (liquid smoke 4% ) and A2 liquid smoke 6%. The treatment without the liquid smoke (A0) increased the TBA value from 0.05 mgMDA/Kg on day (0) to 0.615 mgMDA/Kg on day 6. The treatment of concentration liquid smoke 4% (A1)  increased  from  0.039  mgMDA/Kg  on  day  (0) to  0.395  mgMDA/Kg  on  day  6.  The  treatment  of concentration liquid smoke 6% (A2) increased from 0.031 mgMDA/Kg on day 0 to 0.209 mgMDA/Kg on day 6.
KARAKTERISASI NANOPARTIKEL KITOSAN EKSTRAK DAUN UBIJALAR (Ipomoea batatas L.) MENGGUNAKAN METODE GELASI IONIK Putri, Ade Indriani; Sundaryono, Agus; Chandra, I Nyoman
Alotrop Vol 2, No 2 (2018)
Publisher : FKIP University of Bengkulu

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The purpose of this study is to determine and measure the results of the characterization of Chitosan nanoparticle synthetized from leaves of sweet potato (Ipomoea batatas l.) extracts . The methods used to make nanoparticles is made with Ionic Gelation method based on electrostatic interaction between the Hydroxyl Amine on Chitosan with cluster of negative charge from the polianion NaTPP with conditioned surfactant Tween 80 used as surfactant. Characterization test of nanoparticle morphology in this study obtained using the Fourier Transformation  Infra Red (FTIR), and Particle Size Analyzer (PSA). Results with FTIR characterization test from the obtained Chitosan-white purple sweet potato leaf extract nanoparticles has a cluster of N-H and P = O that show the occurrence of ammonium ion interaction between Chitosan with polianion from NaTPP and sweet potato leaves. The interaction seen from wave number and intensities  O-H shifting from pure Chitosan at 3425.56 cm-1 to 3427, 51 cm-1, as well as on pure Chitosan N-H absorption  undergoes a shift from 1597, 06 cm-1 to becomes 1629.85-1 cm-1, which shows that there has been a cross connective between ammonium ion on Chitosan and Posphat from NaTPP and white purple sweet potato leaf extract. The results of the analysis from the PSA, is known to the average Nanokitosan particle sizes extracts from white purple sweet potato leaf extracts with the addition of NaTPP i.e. of 302.6 nm and that the aim of the research on Chitosan nanoparticle synthesis has been successfully done.
PERBANDINGAN AKTIVITAS DAN HASIL BELAJAR KIMIA SISWA SMAN 2 ARGAMAKMUR PADA PEMBELAJARAN MENGGUNAKAN TEAM ASSISTED INDIVIDUALIZATION DAN GROUP INVESTIGATION BERBASIS KURIKULUM 2013 Dewi, Ria Kemala; Sumpono, Sumpono; Rohiat, Salastri
Alotrop Vol 2, No 2 (2018)
Publisher : FKIP University of Bengkulu

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This research was aimed to know  the differences between the student’s chemical learning activities and achievement by using a models called Team Assisted Individualization and Group Investigation based on Curriculum 2013. The samples in this research is class X MIA 3 (Team Assisted Individualization) and X MIA 6 (Group Investigation). The result of this research is learning activities and achievement and than the analysis used are the score and percentage of mean, normality tests, homogeneity tests, hypothesis tests. The observation result of student’s learning activities in the 1 and 2 of experimental class was 78.79% and 68,18%. The mean score of student’s achievement for experimental class 1 and 2 was 80,56 and 75,31. The result of t test obtained tcount > ttable, 10,6 > 1,0 for learning activities and 3,36 > 2,30 for achievement. It means there was a significant differences between the student’s chemical learning activities and achievement by using both models of learning.
POTENSI SITOTOKSIK DAN ANTIBAKTERI EKSTRAK DAUN Laportea interrupta (L.) Chew (JELATANG AYAM) TERHADAP Staphylococcus aureus Safitri, Okti Mindi; Nurhamidah, Nurhamidah; Amir, Hermansyah
Alotrop Vol 2, No 2 (2018)
Publisher : FKIP University of Bengkulu

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This research aims to determine the profile of phytochemicals, determine the level of cytotoxic extract toward the larva of Artemia salina Leach by using Brine Shrimp Lethality Test (BSLT) method, and to measure how much the activity of  antibacteria leaf ekstract of Laportea Interrupta (L.) Chew  (Jelatang Ayam )  toward the Staphylococcus aureus bacteria. The leaf of L. interrupta  (L.) Chew are dried and grinded well. The half of grinded sample are tested by phytochemical  profile and another one are ekstracted by using etanol liquid for three days then they are evaporated. The result of fitokimia leaf L. interrupta  (L.) Chew test contains secondary metabolite alkaloid,  tanin, terpenoid,  and saponin. The result of cytotoxic extract of leaf L. interrupta  (L.) Chew toward the A. salina Leach is obtained LC50 for 93,33 ppm, so, the L. interrupta  (L.) Chew is toxic because it is in the range of 31 ppm to 1000 ppm and it can be potentially as a anticancer agents. The eksract of Jelatang Ayam leaf can obstruct the growth of S. aureus, on 5 x 104 clear zone concentration that formed 9 mm being medium categorized. The more concentration of the Jelatang leaf ekstract then more its obstruction energy.
PERBEDAAN HASIL PEMBELAJARAN PROBLEM BASED LEARNING (PBL) MENGGUNAKAN MIND MAPPING DAN SUMMARIZES PADA KELAS XI IPA MAN 1 KOTA BENGKULU TAHUN AJARAN 2017/2018 Kasih, Alfia Novera Indah Esa; Bahar, Amrul; Rohiat, Salastri
Alotrop Vol 2, No 2 (2018)
Publisher : FKIP University of Bengkulu

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This study aims to determine differences in ProblemBased learning (PBL) using mind mapping ( PBL-mind mapping) and summarizes (PBL –summarizes) on the subject of ionic equilibrium in saline solution. The type of research used is quasi experimental research with population class XI IPA in MAN 1 Kota Bengkulu 2017/2018 academic year which amounted to 152 people and samples taken from normal and homogenous population by random sampling technique so that got sample that is class XI IPA 1 (PBL -Mind Mapping) as an experiment 1 with 36 people and class XI IPA 2 (PBL-Summarizes) as an experiment 2 which is 38 people.Data obtained in the form of cognitive domain learning results obtained from test results in the form of pretest and post-test. Data analysis used were mean score, normality test, homogeneity test, and hypothesis / t test with significance value ? = 0.05 calculated with SPSS 16.0 for Windows. Student learning outcomes in this study seen from the value of difference between pretest and post-test values. The average of pretest and post-test difference of experimental class 1 and 2 students were 56.11 and 49.21 and t-test obtained t-count value is greater than t-table (2.088> 1.99).The results of the data show that there are significant differences between the experimental classes 1 and 2 and show that the result of learning PBL using mind mapping is better with KKM achievement of 83.4% than the result of learning PBL using summarizes with KKM exhaust amounted to 68.4%.
PENERAPAN MODEL PEMBELAJARAN PROBLEM BASED INSTRUCTION (PBI)DENGAN MENGGUNAKAN MEDIA AUDIO-VISUAL UNTUK MENINGKATKAN AKTIVITAS BELAJARDAN HASIL BELAJAR SISWA DI SMA N09 KOTA BENGKULU Mutaqwiyati, Isna; Nurhamidah, Nurhamidah; Amir, Hermansyah
Alotrop Vol 2, No 2 (2018)
Publisher : FKIP University of Bengkulu

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This research was aimed to find out the student’s improvement of  learning activity and learning outcome as the implementation of  Problem Based Instruction (PBI) by using audio-visual media. The subject of this research was the students at grade X MIPA 3 of SMA N 09 Bengkulu Ciyty academic year of 2017/2018 which consisted of 27 students, on the subject of of chemistry’s basic laws and stoichiometry. This research was conducted by the researcher by using three cycles which consisted of four steps; planning, action, observation and reflection. The data collections were tests and non tests which consisted of post test and student’s learning activity observation sheets. The data of this research was analyzed by using simple quantitative data analysis;   the student’s average score, the percentage of classical absorption and the percentage of classical learning mastery.   Based on the result of this research can be concluded that the implementation of   PBI by using audio-visual media improved student’s learning activity and learning outcomes in each cycle and achieved the clasical learning outcomes in cycle III. The improvements of student’s average score was; score 23 (Fair) of cycle I; score 26,33 (good) of cycle II; and score 28,66 (good) cycle III. The average score of teacher observation sheets of each cycles were; 25,66 fpr the first cycle (good), 28 for the second cycle (good), and 29,66 in the last cycle (good). There  was also  improvements of the students’ percentage of classical learning mastery from in cycle I 51,85%, to 66,66% in cycle II and 85,15% in cycle III.
BIOSORPSI ION LOGAM BERAT Cu(II) DAN Cr(VI) MENGGUNAKAN BIOSORBEN KULIT KOPI TERXANTHASI Adriansyah, Renaldi; Restiasih, Elyn Novta; Meileza, Nessi
Alotrop Vol 2, No 2 (2018)
Publisher : FKIP University of Bengkulu

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There are several methods that have been used to remove and reduce the contamination of heavy metal ions.Among theseveral methods, biosorpsi is a cheap and high efficiency method. One of the organic materials that have potential to become heavy metal ion biosorbent was coffee skin.However, to improve the performance of coffee skin in adsorption of  heavy metal ions Cu (II) and Cr (VI) then biosorbent need to be modified through xanthation process.This xanthation process carried out by reacting the coffee skin with carbon disulfide compounds in an alkaline condition.This study aims to determine the ability of xanthated  coffe  skin biosorbentin adsorption of  Cu (II) and Cr (VI) metal ions and to know the optimum condition of the metal ion adsorption process byxanthated  coffe  skin biosorbent. From this research we got the optimum mass of Cu (II) and Cr (VI) metal ion adsorption of 0.45 and 0.6 gram. The optimum pH of Cu(II) and Cr(VI) metal ions adsorption occurs at pH 4.While the optimum contact time occurs at 100 minutes for Cu (II )metal ion adsorption  and 80 minutes for Cr (VI) metal ion adsorption. In addition, the maximum biosorption capacity of xanthated coffeskin biosorbent in adsorption of Cu (II) and Cr(VI) metal ions respectively 62.5 mg/g and 8.064 mg/g.  So it can be concluded that xanthated  coffe  skin biosorbenthave a better ability to adsorb Cu (II) metal ions than Cr (VI) metal ions.
PENERAPAN MODEL PEMBELAJARAN KOOPERATIF TIPE COURSE REVIEW HORAY(CRH) UNTUK MENINGKATKAN MOTIVASI DAN HASIL BELAJAR KIMIA SISWA SMA N 1 KOTA BENGKULU Zulhulaifah, 1Nurul; Nurhamidah, Nurhamidah; Elvinawati, Elvinawati
Alotrop Vol 2, No 2 (2018)
Publisher : FKIP University of Bengkulu

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This study is a classroom action research applying the Course Review Horay learning model on the subject of basic chemical laws and chemical reaction equations in three cycles with four stages: planning, implementation, observation and reflection on each cycle aimed at improving motivation, activity and results learning chemistry of students of class X IPA 5 SMA N 1 Kota Bengkulu academic year 2017/2018. The study was conducted in March-April of 2018 with a total of 27 students, consisting of 17 women and 10 men. The data were obtained using questionnaire of motivation, posttest and observation sheet of teacher and student activity, which was processed using simple quantitative analysis technique, mean score of motivation questionnaire and observation sheet, percentage of classical absorption and classical learning completeness. From the results of this study it can be concluded that the application of CRH learning model proved able to increase the students' motivation, activity and chemistry learning achievement to reach the minimum mastery criteria of ?75 in the third cycle. Student learning motivation increased every cycle from pre cycle up to cycle III 35,69% (low), 38,95% (low), 59,71% (medium) and 78,96% (high) respectively. The activities of teachers and students also increased each cycle in a row: teacher activity scores: 36, 38 and 38.5 with good category and student activity score: 29 (enough), 37,5 and 38 with good category. Student learning outcomes in cycle I obtained an average value of 54.3; 54.3% classical absorption and 16% classical learning completeness. In cycle II, the average score is 72.5; 72.5% classical absorption and 57.69% classical learning completeness. In cycle III, the average score is 78.76; 78.76% classical absorption and 84.61% classical learning completeness
ANALISIS ION MERKURI (II) MENGGUNAKAN NANO PARTIKEL PERAK TERIMOBILISASI PADA KERTAS SARING Meileza, Nessi; Firdaus, M. Lutfi; Elvinawati, Elvinawati
Alotrop Vol 2, No 2 (2018)
Publisher : FKIP University of Bengkulu

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The aims of this research is improve stability and sensitivity of silver nanoparticles (NPP) immobilizatied on filter paper. Silver nanoparticles synthesized by reducing the ascorbic acid using a chemical reduction method. Immobilization NPP on filter paper is done with the technique of immobilization (immunosystem) is the process of molecular bonding reagent in supporting materials, so physically bound NPP the surface of filter paper is composed of cellulose fibers. The results obtained for the stability of immobilization NPP on filter paper can be last up to stable 60-daywhile liquid NPP stability can only last for 30 days. To maintained the stability ofimmobilization on filter paper is saved in a closed box. For the determination of sensitivity of immobilization NPP in the filter paper test is performed against the mercury (II) ion with each different concentrations. The results obtained for sensitivity of immobilization NPP on the filter paper is analyzed in digital image can be detect mercury (II) ion until the concentration of ppb. The results of measurement Limit of Detection (LOD) or limit the smallest NPP can detect mercury (II) ion is under 0.863 ppb, while liquid NPP able to detect only concentration 1.448 ppb.. The results of this research NPP immobilization on filter paper can be an alternative to increasingstability and sensitivity of NPP compared with liquid  NPP, and can be applied into the colourimetry indicator is inexpensive and practical to analysis of mercury (II) ion in the digital image.

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