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Elvinawati Elvinawati
Universitas Bengkulu
Chemistry Education

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KARAKTERISASI ISOTERM ADSORPSI DARI ION LOGAM BESI (Fe) PADA TANAH DI KOTA BENGKULU Hesti Apriyanti; I Nyoman Candra; Elvinawati Elvinawati
ALOTROP Vol 2, No 1 (2018)
Publisher : University of Bengkulu

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33369/atp.v2i1.4588

Abstract

[CHARACTERIZATION OF THE  ADSORPTION FROM IRON METAL IONS ISOTHERM ON THE SOIL IN BENGKULU CITY] Level of micronutrient elements Fe takes part in determining the fertility rate of agricultural land. Continuous oxidation of Fe the soil will cause soil poisoning, due to the soil saturated in absorb of Fe. This research aims to determine the characteristics of the soil, adsorption and its ability in absorption isotherm on  Fe metal. Soil samples were taken from the farm in the city of Bengkulu. The characteristics of the soil tested, i.e., water content, pH, and soil type. Adsorption isotherm type is a determination as Langmuir or  Freundlich isotherm. Soil sample after it is dried and cleaned and then milled and sieved at 100 mesh sieve. Moisture content is measured by dried in an oven for 24 hours and the measurement of the difference between the initial and the final weight of the soil. Determination of soil pH is measured by the pH meter on the CaCl2, and soil type is determined by calculating the percentage of sand, silt, and clay from the soil. Maximum adsorption capacity is determined from Fe adsorption isotherm after getting the pH, the weight of adsorbent and optimum contact time. Adsorption Isotherm was determined by adsorption of aqueous Fe variation at the concentration of  2.5; 5; 10; 15; 20; and 25 ppm on optimum pH and weight, and stirred at an optimum contact time, then filtered and measured its absorbance with UV-Vis spectrophotometer. Results of research results in the form of moisture content average 23.5%, soil pH value at 5 and soil type, i.e., dusty clay with the dominant form of Isotherm adsorption is a Freundlich isotherm, and the capacity of soil in adsorbing of iron on this research obtained is amounting to 45.6.
UJI EFEKTIFITAS ASAP CAIR CANGKANG BUAH KARET (Hevea braziliensis) SEBAGAI ANTIBAKTERI Bacillus subtilis Lia Retno Sari; Sumpono Sumpono; Elvinawati Elvinawati
ALOTROP Vol 3, No 1 (2019)
Publisher : University of Bengkulu

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33369/atp.v3i1.9033

Abstract

The purpose of this research was know the effectiveness quid smoke the liquid smoke of the rubber (Hevea braziliensis)  shell.The manifacture and purification of liquid smoke is carried out by 4 stages: pyrolysis, sedimentation, distillation, redestilate. The first of the research is calculating phenol levels, total acid, pH, and type weights The results showed that the feeding of rubber  (Hevea braziliensis) shell liquid Smoke proved to inhibit the growth of bacteria Bacillus subtilis where the higher the concentration of liquid smoke, the greater the resistance. The phenol levels contained in the liquid smoke of the rubber shells were obtained at 0.84% with a total acid rate of 4.725%, and a  pH at  2.548 and a density at 1.004. Antibacterial test using disc paper with see diameter clear zone. Bacterial using is pure cultur Bacillus subtiis bacteria. The concentration liquid smoke to antibacteral test is 5%, 10%, 15%, 20% and 25%. Of the five treatment obtained KHM 20% with diameter clear zone is 5,21 mm. Analysis results using One Way ANOVA obtained F hitung ? f tabel then there Significant differences Against the resulting clear zone.
UPAYA PENINGKATAN SENSITIVITAS NANOPARTIKEL PERAK UNTUK ANALISIS ION MERKURI(II) SECARA CITRA DIGITAL DENGAN PENAMBAHAN NaCl Edo Prasetia; M. Lutfi Firdaus; Elvinawati Elvinawati
ALOTROP Vol 3, No 2 (2019)
Publisher : University of Bengkulu

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33369/atp.v3i2.10120

Abstract

The very small concentration of mercury (Hg) in the environment is difficult to detect, so an accurate and sensitive method is needed in order to detect the concentration. Therefore, the purpose of this study was to develop an accurate and sensitive method based on the use of digital imaging methods and silver nanoparticles (AgNPs) as colorimetric sensors for mercury(II) ions (Hg2+) analysis. The process of making AgNPS is done by a bottom up method involving a reduction reaction. The precursor used is 1 mM AgNO3 solution and as bioreductor is an antioxidant compound present in extract of chili pepper (Capsicum frutescens L) with ratio 1: 9. Contact time variation 15, 30, 45, 60 min and 1, 2, 7 days. Addition of NaCl 0.5 and 1 M NaCl were used to increase the sensitivity of AgNPs as colorimetric sensors of Hg2+ ions. Digital Image Method is used to analyze Hg2+ ions at ppb concentration level. The results of the most optimum silver nanoparticles synthesized at the time of solar heating is 60 minutes. The addition of NaCl 0.5 M and 1 M into AgNPs is able to increase the sensitivity of AgNPs. Limit of Detection (LoD) of AgNPs added NaCl 0.5 M and 1 M was able to detect Hg2 + ions by 3.02 ppb and 2.46ppb.
HUBUNGAN IMPLEMENTASI CONTEXTUAL TEACHING AND LEARNING (CTL) DENGAN HASIL BELAJAR SISWA MATA PELAJARAN KIMIA DI KELAS X MIA SMA NEGERI 8 KOTA BENGKULU Pebri Tri Andiko; Salastri Rohiat; Elvinawati Elvinawati
ALOTROP Vol 3, No 1 (2019)
Publisher : University of Bengkulu

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33369/atp.v3i1.9041

Abstract

This study aims to analyze the relationship of Contextual Teaching and Learning (CTL) implementation with students' learning outcomes in X class MIA SMA Negeri 8 Kota Bengkulu at 2017/2018 Academic year. This type of research is correlational research. The population in this research is class X MIA SMA Negeri 8 Kota Bengkulu 2017/2018 Academic year and research using total sampling technique where all population used also become sample of research with total 166 students. Data collection techniques in this study using questionnaires, observation sheets and students' chemistry learning results. Data analysis using Pearson correlational analysis and validation test, reliability, normality, linearity (with F test) , and hypothesis test. Based on the results of data analysis that has been done, obtained general conclusion of a positive relationship between the application of Contextual Teaching and Learning (CTL) with the results of students learningoutcomes in X class MIA SMA Negeri 8 Kota Bengkulu at 2017/2018 Academic year, indicated by the value rhitung obtained greater than the value of tabell r (0.704> 0.1281) with the level of correlation into the category of strong / high, it means there is a positive and strong relationship between the application of Contextual Teaching and Learning with student learning outcomesin X class MIA SMA Negeri 8 Kota Bengkulu at 2017/2018 Academic year.
PENERAPAN MODEL PEMBELAJARAN INKUIRI DENGAN MEDIA DART BOARD UNTUK MENINGKATKAN HASIL BELAJAR KIMIA Di KELAS XI IPA 1 SMA NEGERI 9 KOTA BENGKULU TAHUN AJARAN 2016/2017 Defrilina Sri Eka Wulandari; Amrul Bahar; Elvinawati Elvinawati
ALOTROP Vol 2, No 1 (2018)
Publisher : University of Bengkulu

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33369/atp.v2i1.4600

Abstract

[THE  APPLICATION OF INQUIRY LEARNING MODEL WITH  DART BOARDMEDIA TO IMPROVE THE STUDIED RESULTS OF  CHEMISTRY IN CLASS XI IPA 1 SMA NEGERI 9 CITY OF BENGKULU  AT 2016/2017 ACADEMIC YEAR]  This research aims to improve the learning outcomes and student activity model of learning by implementing a inkuiri dart board with media in class XI IPA 1 SMA Negeri 9 Bengkulu city at 2016/2017. Academic year. This research is a class action research. This research was conducted in three cycles consisting of 4 stages each namely planning, implementation, observation, and reflection. The subject of this research is the whole grade X IPA 1 SMA N 9 Bengkulu city on 2016/2017 academic year. From the results, it can be concluded that the process of learning to apply inquiry learning models by using a Dart Board media proved can improve the activity and outcomes of study chemistry grade XI IPA 1 SMA Negeri 9  Bengkulu city on 2016/2017 academic year. It can be seen from the average value of students in Ist cycle are 61.61, classical absorption 77.02% and learning of classical completeness at 19.35%..In Iind Cycle obtained an average score of students amounted to 71.29; absorption of conventional 79.21% and  completeness studied conventional 35.48%. In IIIth cycle received an average rating of students at 84.51; absorption of conventional 84.51% and  completeness  studied classical 90.32%.. For the entire sequence of an increase in the activity of the students which can be seen from the mean value – 1st cycle averages of 22.5, 2nd cycle at 25; and in 3th cycle at 29.
HUBUNGAN ANTARA SARANA LABORATORIUM TERHADAP KETERAMPILAN PROSES SAINS SISWA KELAS XI MIPA 5 DI SMA NEGERI 3 KOTA BENGKULU Nola Desti Pratiwi Simanjuntak; Salastri Rohiat; Elvinawati Elvinawati
ALOTROP Vol 1, No 2 (2017)
Publisher : University of Bengkulu

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33369/atp.v1i2.3511

Abstract

[RELATIONSHIP BETWEEN LABORATORY FACILITIES AND  STUDENT PROCESS SKILLS AT CLASS XI MIPA 5 IN SMA NEGERI 3 KOTA BENGKULU] The purpose of this study was to determine the relationship of laboratory facilities to students' science process skills in the laboratory. This research is a correlational research. The population in this study is all students of class XI MIPA 5 academic year 2016/2017 in SMA Negeri 3 Kota Bengkulu. This research uses total sampling technique so that the entire population is used as research sample. The independent variable (x) in this research is chemical laboratory equipment and dependent variable (y) is the science process skill of students in laboratory of SMA Negeri 3 Kota Bengkulu.. Data collection in this research using questionnaire instrument with 30 items and observation sheet with 15 items . Technique of data analysis using expert validity test, questionnaire analysis, observation analysis of science process skill, normality test, linearity test, correlation analysis and hypothesis test. Data analysis using the help of SPSS 16 program. The results of data processing correlation coefficient (r) obtained that is equal to 0.387 at 5% significance level. . The result of hypothesis test shows that Ha is accepted which means there is a significant correlation between laboratory facilities and science process skill of students in laboratory on chemistry learning of students of class XI MIPA 5 SMA Negeri 3 Kota Bengkulu academic year 2016/2017
PENERAPAN MODEL PEMBELAJARAN KOOPERATIF TIPE COURSE REVIEW HORAY(CRH) UNTUK MENINGKATKAN MOTIVASI DAN HASIL BELAJAR KIMIA SISWA SMA N 1 KOTA BENGKULU 1Nurul Zulhulaifah; Nurhamidah Nurhamidah; Elvinawati Elvinawati
ALOTROP Vol 2, No 2 (2018)
Publisher : University of Bengkulu

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33369/atp.v2i2.7484

Abstract

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 Nessi Meileza; M. Lutfi Firdaus; Elvinawati Elvinawati
ALOTROP Vol 2, No 2 (2018)
Publisher : University of Bengkulu

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33369/atp.v2i2.7559

Abstract

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.
PENERAPAN MODEL DISCOVERY LEARNING DENGAN MENGGUNAKAN MEDIA VIDEO UNTUK MENINGKATKAN AKTIVITAS BELAJAR DAN HASIL BELAJAR SISWA KELAS XI IPA 1 SMAN 1 KOTA BENGKULU Sitti Utami Medianty; Amrul Bahar; Elvinawati Elvinawati
ALOTROP Vol 2, No 1 (2018)
Publisher : University of Bengkulu

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33369/atp.v2i1.4689

Abstract

[APPLICATION OF DISCOVERY LEARNING MODEL BY USING VIDEO MEDIA TO INCREASE LEARNING ACTIVITIES AND STUDENT LEARNING RESULT CLASS XI IPA 1 SMAN 1 BENGKULU CITY]. The research has goals to improve the activity and learning outcomes chemistry at XI IPA 1 class in SMA Negeri 1 Bengkulu that consist of 30 students: 23 girls and 7 boys. This study is research of class action on thermochemistry subjects by discovery learning model. This research consist three cycle on four stage: planning, action, absorption, and reflection. The data collected using test and non test that consist of post test and observation sheet of activity teacher and student. The data processed using quantitative simple analysis techniques: average score of observation sheet of activity teacher and student, average score, absorption percentage clasical, andclasssical learning completness percentage. From the reseult, we can conculded that chemistry learning process applying discovery learning model using video can improve activity and outcomes learning chemistry student. It can be see from the average score of students. In the first cycle is 69.33 in which the percentage of classical absorption is 86.67 and classical learning completeness is 66.67. The average score of the second cycle is 71,33 in which the percentage of classical absorption is 89.17 and classical learning completeness is 73.33. The students’ average score of the third cycle is 81.33 in which the percentage of classical absorption is 90.37 and classical learning completeness is 86.67. The teacher’s activities of the learning process in the first cycle get average score 26.5 and it is good category, the second cycle is 27.5 and it is good category, the third cycle is 30 and it is good category too. Meanwhile, the student’s activities in the first cycle get average score 22.5 and it is good category, the second cycle is 25 and it is a good category, the third cycle is 27 and it is good category.
PEMANFAATAN EKSTRAK AIR BUAH Flacourtia inermis Roxb. (LOBI-LOBI) SEBAGAI PENGAWET IKAN LAUT Ade Pribadi; Nurhamidah Nurhamidah; Elvinawati Elvinawati
ALOTROP Vol 2, No 1 (2018)
Publisher : University of Bengkulu

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33369/atp.v2i1.4581

Abstract

[THE  UTILIZATION OF   Flacourtia inermis Roxb. (LOB-LOBI ) FRUIT WATER EXTRACTS AS A MARINE FISH PRESERVATIVE] This research aims to determine the magnitude of the concentration and the length of time the optimum soaking water extracts of fruit Flacourtia inermis Roxb. (lobi-lobi ) as well as measuring its potential for use as a preservative in marine fish. Sample marine fish used is Kerapu Macan (Epinephelus fuscogultatus). The concentration of water extract from the fruit of F.inermis Roxb  is at levels at 10, 20, 30 and 40% with soaking time each at 1, 2 and 3 hours for any variation of the concentration. Observation of the level of the fish freshness is done with a variety of storage time of 12, 18, and 24 hours at room temperature to any variation of the concentration of extract and soaking time. The parameters used in determining the level of the freshness of the sample fish is a rate of Total Volatile Bases (TVB), moisture content, and pH. The results of the research done indicate that extracts water from the fruit of F.inermis Roxb L are potential for use as a preservative of marine fish based on the values of pH and the levels of TVB. The most optimum concentration and soaking time in Kerapu Macan fish preserve during its storage was soaking with a concentration of 30% for 1 hour, i.e., able to withstand the pace of the decline of the quality of the Kerapu Macan sample for 18 hours at room temperature: with the pH 6.7 and fish TVBvalue at 29.4 mgN/100 g.
Co-Authors 1Nurul Zulhulaifah Ade Pribadi Aisha Syafitri Amrul Bahar Amrul Bahar Defrilina Sri Eka Wulandari Edo Prasetia Fikri Ananda Fikri Fadillah Azhar Hermansyah Amir Hesti Apriyanti I Nyoman Candra Junaini Junaini Lia Retno Sari M. Lutfi Firdaus Nessi Meileza Nola Desti Pratiwi Simanjuntak Nurhamidah Pebri Tri Andiko Renaldi Adriansyah Salastri Rohiat Sitti Utami Medianty Sumpono Sumpono