Elfi Susanti VH
Department of Chemistry, PMIPA FKIP, Sebelas Maret University, Jl. Ir Sutami 36 A Surakarta 53126

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STUDI KOMPARASI PENGGUNAAN METODE KOOPERATIF STAD (Student Team Achievement Division) DISERTAI MEDIA SUPLEMEN LATIHAN BERSTRUKTUR DAN MEDIA DIAGRAM TERHADAP PRESTASI BELAJAR KONSEP MOL SISWA KELAS X MAN WONOGIRI TAHUN PELAJARAN 2008/2009 Rahmawati, Ani; Susanti VH, Elfi; Redjeki, Tri
Jurnal Pendidikan Kimia (JPK) Vol 1, No 1 (2012)
Publisher : Program Studi Pendidikan Kimia FKIP UNS

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Abstract

Tujuan penelitian ini adalah untuk mengetahui prestasi belajar siswa pada materi pokok Konsep Mol melalui proses pembelajaran menggunakan metode STAD dilengkapi media suplemen latihan berstruktur lebih baik dibandingkan prestasi belajar siswa dengan menggunakan metode STAD dilengkapi media diagram. Penelitian ini menggunakan metode eksperimen dengan desain penelitian“Randomized Group Pretest-Posttest Design”. Populasi penelitian ini adalah siswa kelas X semester 1 MAN Wonogiri tahun ajaran 2008/2009. Sampel terdiri dari 2 kelas, yaitu kelas X.C sebagai kelas eksperimen 1 dan kelas X.B sebagai kelas eksperimen 2 yang dipilih secara cluster random sampling. Data utama penelitian ini berupa prestasi belajar siswa yang diperoleh dari aspek kognitif dan aspek afektif. Aspek afektif hanya diberikan pada posttest. Analisis data untuk pegujian hipotesis dilakukan menggunakan uji t-pihak kanan. Hasil penelitian dapat disimpulkan bahwa pencapaian prestasi belajar siswa pada pembelajaran kimia materi pokok Konsep Mol dengan metode pembelajaran STAD (Student Team Achievement Division) disertai media suplemen latihan berstruktur lebih baik dibandingkan dengan metode pembelajaran STAD yang disertai media diagram. Hasil analisis data menggunakan uji t-pihak kanan diperoleh prestasi belajar siswa kelas eksperimen STAD yang disertai latihan berstruktur lebih baik daripada kelas eksperimen STAD yang disertai media diagram untuk aspek kognitif (thitung > ttabel = 2,71 >1,66 ) dan aspek afektif (thitung > ttabel = 2,61 > 1,66 ).   Kata kunci : STAD , latihan berstruktur, media diagram, konsep mol
SYNTHESIS, CHARACTERIZATION AND ANTIOXIDANT ACTIVITY OF 7-HYDROXY-3,4-DIMETHOXYFLAVONE Susanti VH, Elfi; Matsjeh, Sabirin; Wahyuningsih, Tutik Dwi; Mustofa, Mustofa; Redjeki, Tri
Indonesian Journal of Chemistry Vol 12, No 2 (2012)
Publisher : Universitas Gadjah Mada

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Abstract

Synthesis of flavones and their derivatives has attracted considerable attention due to their significant pharmaceutical effects. 7-hydroxy-3,4-dimethoxyflavone has been synthesized and its antioxidant activity has been investigated. Flavone was synthesized by oxidative cyclization of chalcone. 2,4-dihydroxy-3,4-dimethoxychalcone was prepared by Claisen-Schmidt condensation of 2,4-dihydroxyacetophenones with 3,4-dimethoxybenzaldehydes in the presence of aqueous solution of sodium hydroxide and ethanol at room temperature. Oxidative cyclization of 2,4-dihydroxy-3,4-dimethoxychalcone was done by using I2 catalyst in DMSO to form 7-hydroxy-3,4-dimethoxyflavone. The synthesized compounds were characterized by means of their UV-Vis, IR, 1H-NMR and 13C-NMR spectral data. The compound was tested for their antioxidant activities by DPPH method.
ACTIVITY TEST OF GUAVA (Psidium guajava L.) LEAF METHANOL EXTRACT AS CONTRACEPTION ANTIFERTILITY TO WHITE MICE (Rattus norvegicus) Ariani, Sri Retno Dwi; Susilowati, Endang; Susanti VH, Elfi; Setiyani, Setiyani
Indonesian Journal of Chemistry Vol 8, No 2 (2008)
Publisher : Universitas Gadjah Mada

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Abstract

The aim of this research is to know about if the guava (Psidium guajava L.) leaf methanol extract on 10.5 mg/mL and 21.0 mg/mL dossages indicate a positive test as contraception antifertility to white mice (Rattus norvegicus). The sample is guava leaf from Mungkid, Magelang Central of Java Indonesia. The animals experiment are the white mice on 140-300 g for female, 200-250 g for male and about 3 months of age in average. The steps of this research are : (1) preparing  sample, i.e. washing, drying on to indirect sunlight and make the sample into powder, (2) isolation the guava leaf powder in soxhlet instrument with hexane, (3) evaporation the sample with rotary evaporator until guava leaf hexane extract produced, (4) maseration the sample with methanol, (5) evaporation the sample with rotary evaporator until guava leaf methanol extract produced, (6) conducting contraception antifertility activity test to guave leaf methanol extract on 10.5 mg/mL and 21.0 mg/mL dossages to mice white. The results of this research are guava leaf methanol extract on 10.5 mg/mL and 21.0 mg/mL dossages indicate a negative contraception antifertility test to white mice but in these dossages have indicated that an antiimplantation effect (the total natality of fetus is less than the total implantation site in mice white).   Keywords: Guava leaf, contraseption antifertility, methanol extract, white mice, implantation
Analysis of High School Students’ Argumentation Ability in the topic of Buffer Solution Devi, Ninda Dwi Cahya; Susanti VH, Elfi; Indriyanti, Nurma Yunita
JKPK (Jurnal Kimia dan Pendidikan Kimia) Vol 3, No 3 (2018): JKPK( Jurnal Kimia dan Pendidikan Kimia)
Publisher : Program Studi Pendidikan Kimia FKIP Universitas Sebelas Maret

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Abstract

Argumentation is scientific discourse in science learning that is used as a link between knowledge from an environment and concepts in science learning. Through argumentation skills can be controlled student understanding in connecting facts with concepts in learning. This study aims to analyze students' argumentation ability on buffer solution subject. Students' argumentation ability is divided into 4 levels; level 1 (claims), level 2 (claims with data), level 3 (claims with data and one rebuttal), and level 4 (claims with more than one rebuttal). Data analysis was done by a qualitative descriptive method using a case study method. The case study method was chosen so that a study of 92 students who were research participants could be carried out in depth and comprehensive. The results obtained that the students' argumentation ability was at level 1 and level 2 argumentation. This shows that students' argumentation skills are still at low and medium levels. The results of this study can be used as a basis for improving the quality of teaching and further research.
Cinnamon Oil as an Antibacterial Agent on Natural Paper from Banana Peel (Musa paradisiaca Linn.) Setyowati, Widiastuti Agustina Eko; Susanti VH, Elfi; Alviah, Iis; Wardani, Melati Kusuma
JKPK (Jurnal Kimia dan Pendidikan Kimia) Vol 4, No 1 (2019): JKPK ( Jurnal Kimia dan Pendidikan Kimia)
Publisher : Program Studi Pendidikan Kimia FKIP Universitas Sebelas Maret

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Abstract

The research about the use of cinnamon oil as an antibacterial agent on natural paper from Banana (musa paradisiaca Linn.) Peel has been conducted. The preparation of the paper using alkalization method, with the use of NaOH 4% at the temperature of 100oC for 1.5 hours. The paper is made in two variations, ie with additive cinnamon oil and without additive. The natural paper produced are tested for pH based on SNI ISO 6588-1.2010 and water content by dry-oven method based on SNI ISO 287:2010. The antibacterial activities were tested against Staphylococcus aureus and Escherichia coli using Kirby-Bauer disc diffusion method. The paper produced meet the standard of ISO 6519:2016 about Basic Paper for Laminated Plastic Wrapping Paper within the parameter of pH and water content. The results showed that the paper with additive cinnamon oil have antibacterial activity againts S. aureus and E. coli with inhibition diameter zone 15 mm and 13 mm respectively, whereas paper without cinnamon oil additives has no antibacterial activity against either S. aureus or E. coli.  These result indicate that cinnamon oil can be used as an antibacterial agent on the natural paper from Banana peel (musa paradisiaca Linn.).