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Siti Marfuah

Other affiliations: State University of Semarang
Bio: Siti Marfuah is an academic researcher from State University of Malang. The author has contributed to research in topics: Catalysis & Chemistry. The author has an hindex of 5, co-authored 28 publications receiving 124 citations. Previous affiliations of Siti Marfuah include State University of Semarang.

Papers
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Journal ArticleDOI
28 Dec 2018
TL;DR: In this article, the level of understanding of acid-base concept in the macroscopic aspect was determined at a level of microscopic, microscopic, and symbolic representation of class XI Science one of Senior High School in Blitar academic year 2017/2018.
Abstract: ABSTRAK : Penelitian ini bertujuan untuk mengetahui tingkat pemahaman konsep asam basa pada tingkat representasi makroskopik, mikroskopik, dan simbolik pada materi asam-basa siswa kelas XI MIA salah satu SMA Negeri di Blitar tahun ajaran 2017/2018. Instrumen penelitian berupa soal tes pilihan ganda beralasan. Hasil penelitian: (1) tingkat pemahaman konsep asam basa pada aspek makroskopik tergolong tinggi, 73,18%, (2) tingkat pemahaman konsep pada aspek mikroskopik tergolong rendah, 50,74%, (3) tingkat pemahaman konsep pada aspek simbolik tergolong cukup, 61,21%, dan (4) hasil korelasi antara representasi makroskopik-mikroskopik tergolong sedang (0,573), hasil korelasi antara representasi makroskopik-simbolik tergolong sedang (0,421) dan hasil korelasi antara mikroskopik-simbolik tergolong kuat (0,675). Kata Kunci : pemahaman konsep, tingkat representasi, makroskopik, mikroskopik, simbolik, asam basa. ABSTRACT : This research aims to determine the level of understanding the concept of acid base at the level of macroscopic, microscopic, and symbolic representation of class XI Science one of Senior High School in Blitar academic year 2017/2018. The research instrumens in the form of reasoned multiple choice. The results show that: (1) the level of understanding of acid-base concept in the macroscopic aspect belong to high category, 73.18%, (2) the level of understanding of the concept on the microscopic aspect classifying to low category, 50.74%, (3) the level of understanding of the concept on the symbolic aspect classifying to the category enough, 61.21%, and (4) the correlation result between macroscopic-microscopic representation belong to medium category (0,573), result of correlation between macroscopic-symbolic representation classified in medium category (0,421) and result of correlation between microscopic-symbolic belong to strong category (0,675). Keywords: understanding concept, degree of representation, macroscopic, microscopic, symbolic, acid-base.

8 citations

Journal ArticleDOI
TL;DR: In this article, the fatty acid methyl ester was produced from transesterification reaction of tamarind seed oil with methanol and boron trifluoride catalyst (MeOH/BF3).
Abstract: The research was conducted to investigate the oil and fatty acids contained in Tamarindus indica Linn (tamarind) seeds oil. Tamarind seeds oil was isolated by extraction and fractionation. The fatty acids content in oil were identified as fatty acid methyl ester. Fatty acid methyl ester was produced from trans-esterification reaction of tamarind seed oil with methanol and boron trifluoride catalyst (MeOH/BF3). Identification of fatty acid methyl ester was carried out by gas chromatograph mass spectrometry (GC-MS). The fatty acids in the Tamarindus indica seed oil are saturated and unsaturated fatty acids. The saturated fatty acids are octanoic (12.66%), decanoic (1.68%), dodecanoic (25.18%), tetradecanoic (5.17-7.83%), hexadecanoic (9.90-16.06%), octadecanoic (3.82-4.80%), eicosanoic (0.39-1.55%), docosanoic (1.00-2.01%), and tetracosanoic (1.92-4.54%) acids. The unsaturated fatty acids are 11-octadecenoic (19.93%), 11-eicosenoic (0.76-1.03%), 9,12-octadecadienoic (21.91-38.68%), and 9-octadecenoic (17.76%) acids. The physical and antibacterial properties of the seed oil are also reported.

8 citations

Journal ArticleDOI
TL;DR: This study aimed to investigate the effect of multimedia teaching materials to students’ learning outcomes and perceptions in organic chemistry I courses and the results obtained were very positive with an increase to the learning outcomes.
Abstract: Penelitian ini bertujuan untuk mengetahui pengaruh bahan ajar multimedia terhadap hasil belajar dan persepsi mahasiswa pada matakuliah kimia organik I. Sebanyak 31 mahasiswa sebagai sampel diberikan pretes dan postes, serta angket untuk mengetahui reaksi mereka terhadap bahan ajar multimedia. Hasil yang diperoleh sangat positif dengan menghasilkan peningkatan terhadap hasil belajar. Mahasiswa merasa senang, termotivasi, dan tertarik untuk belajar kimia organik I dengan bahan ajar multimedia. Mahasiswa berharap pembelajaran lainnya bisa menggunakan multimedia. This study aimed to investigate the effect of multimedia teaching materials to students’ learning outcomes and perceptions in organic chemistry I courses. There were 31 university students as a sample that given pre-and posttest, and a survey to ascertain their reactions toward the multimedia teching material. The results obtained were very positive with an increase to the learning outcomes. Students felt happy, motivated, interested in learning organic chemistry I with multimedia teaching material. Students expected that the other learning could used multimedia.

8 citations

Journal ArticleDOI
TL;DR: In this paper, the influence of journal learning in the implementation of Learning Cycle 6E for metacognitive awarness of the students SMAN 8 Malang in the material of redoks.
Abstract: This study aims to know the different influence of journal learning in the implementation of Learning Cycle 6E for metacognitive awarness of the students SMAN 8 Malang in the material of redoks. The research method is using quasy experiment with the kinds of pretest and posttest design. The data is collected by 52 statements in questioners of metacognitive awarness. The result of this study shows that there is the different metacognitive awarness for students who are learning by Learning Cycle 6E guided by journal of learning, and the students who are learning by Learning Cycle 6E without journal of learning. Penelitian ini bertujuan untuk mengetahui perbedaan pengaruh jurnal belajar dalam model pembelajaran Learning Cycle 6E terhadap kesadaran metakognitif siswa SMAN 8 Malang pada materi redoks. Rancangan penelitian yang digunakan adalah Quasy Experiment Design dengan jenis pretest posttest design. Data dikumpulkan dengan 52 pernyataan kuesioner kesadaran metakognitif. Hasil penelitian menunjukkan bahwa ada perbedaan kesadaran metakognitif siswa yang dibelajarkan dengan model pembelajaran Learning Cycle 6E dipadu jurnal belajar dan menggunakan model pembelajaran Learning Cycle 6E tanpa jurnal belajar pada materi redoks.

8 citations

Journal ArticleDOI
01 May 2020
TL;DR: In this paper, the authors used peel's extract of kepok, ambon, and tanduk bananas (Musa paradisiaca L, Musa acuminata Cavendish Subgroup, and Musa x paradisicaa) as a capping agent to synthesize ZnO nanoparticles.
Abstract: One of the nanoparticles used in the medical world is ZnO nanoparticles The purpose of this study was to synthesize ZnO nanoparticles by using peel's extract of kepok, ambon, and tanduk bananas (Musa paradisiaca L, Musa acuminata Cavendish Subgroup, and Musa x paradisiaca) as a capping agent This research was conducted in four main steps, namely: extraction of three kind of bananas peel, phytochemical test on the bananas peel extract, synthesis of ZnO nanoparticles by using the extracts, characterization of ZnO nanoparticles by X-Ray Diffraction (XRD), and antibacterial activity test of ZnO nanoparticles Based on the phytochemical test it was proven that bananas peel extract contained secondary metabolite such as flavonoids, polyphenols, alkaloids, and saponins in various concentration The XRD analysis concluded that ZnO nanoparticles were successfully synthesized Through the agar diffusion test, it can be showed that ZnO nanoparticles are a promising material as antibacterial agents This statement is based on evidence that the diameter of the clear zone produced ranges from 8 to 10 nm

6 citations


Cited by
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07 Feb 2015

3,695 citations

Journal ArticleDOI
TL;DR: The square planar Ag(I) ion is a rare ion, with only ∼2% of all reported silver complexes possessing this stereochemistry as discussed by the authors, despite the fact that there are currently around 65 well characterised complexes containing squareplanar Ag (I) ions, about half of which are coordination polymers.

204 citations

Journal ArticleDOI
TL;DR: In this article, the I1O1 and I2O0 connectivity of compounds with aromatic carboxylate ligands has been investigated for single crystal X-ray diffraction.
Abstract: Solvothermal reactions of Ca(NO3)2 or Ba(NO3)2 with aromatic carboxylate ligands afforded four new inorganic–organic hybrid frameworks, [Ca(PBDC)(H2O)3]n (1), [Ca(OBDC)(H2O)]n (2), [Ba5(OBDC)4(H2O)2(NO3)2]n (3), and [Ba3(BTC)2(H2O)4]n (4) (H2PBDC = terephthalic acid, H2OBDC = phthalic acid, H3BTC = 1,3,5-benzenetricarboxylic acid). These compounds have been fully characterized by single crystal X-ray diffraction, powder X-ray diffraction, satisfactory elemental analysis, IR spectra, and TG analysis. X-ray analysis shows that compound 1 features a one-dimensional chain (1D) structure with the I1O0 connectivity, both compound 2 and compound 3 feature a two-dimensional (2D) layer structure with the I1O1 connectivity, I2O0 connectivity, respectively, compound 4 features a three-dimensional (3D) framework with a rare I3O0 connectivity. Thermal stabilities and luminescent properties of compounds 1–4 and NLO property of compound 4 have also been investigated.

103 citations

Journal ArticleDOI
TL;DR: complexes 1-5 have been found to display effective antimicrobial activity against the series of bacteria and fungi, and some of them are potential candidates for antiseptic or disinfectant drugs.
Abstract: Five new silver(I) complexes of formulas [Ag(Tpms)] (1), [Ag(Tpms)(PPh3)] (2), [Ag(Tpms)(PCy3)] (3), [Ag(PTA)][BF4] (4), and [Ag(Tpms)(PTA)] (5) {Tpms = tris(pyrazol-1-yl)methanesulfonate, PPh3 = triphenylphosphane, PCy3 = tricyclohexylphosphane, PTA = 1,3,5-triaza-7-phosphaadamantane} have been synthesized and fully characterized by elemental analyses, 1H, 13C, and 31P NMR, electrospray ionization mass spectrometry (ESI-MS), and IR spectroscopic techniques. The single crystal X-ray diffraction study of 3 shows the Tpms ligand acting in the N3-facially coordinating mode, while in 2 and 5 a N2O-coordination is found, with the SO3 group bonded to silver and a pendant free pyrazolyl ring. Features of the tilting in the coordinated pyrazolyl rings in these cases suggest that this inequivalence is related with the cone angles of the phosphanes. A detailed study of antimycobacterial and antiproliferative properties of all compounds has been carried out. They were screened for their in vitro antimicrobial activi...

78 citations

Journal ArticleDOI
TL;DR: New coordination polymers have been obtained by the self-assembly of silver salts AgX and 2,4-diamino-6-R-1,3,5-triazines L of formulas AgLX and a new species has been detected at low temperatures, and this exhibits restricted rotation of the phenyl ring.
Abstract: New coordination polymers have been obtained by the self-assembly of silver salts AgX (X = BF4, PF6, CF3SO3) and 2,4-diamino-6-R-1,3,5-triazines L (R = phenyl and p-tolyl) of formulas AgLX (1−6). A complex of different stoichiometry, [Ag3L2(H2O)(acetone)2](BF4)3, 7 (R = phenyl), has also been synthesized. The three-dimensional structures of five compounds have been determined by X-ray diffraction studies. For the AgLX complexes, when X = BF4 and R = phenyl or p-tolyl, chiral chains with alternating Ag and L are formed. The chains are cross-linked by the counteranions in a three-dimensional fashion through hydrogen bonds and weak Ag···F interactions giving rise to a structure with solvent-filled channels. Different and more compact structures have been found when the counteranion is CF3SO3 (OTf). When R = phenyl, sheets are formed which consist of [Ag2(OTf)2L2] units with double triflate bridges and which contain columns of π−π stacked arenes. Hydrogen bonds connect the sheets. When AgOTf is used and R is ...

59 citations