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EFFECT OF SCANDIUM ON HIDROGEN DISSOCIATION ENERGY AT MAGNESIUM SURFACE: AB INITIO DFT STUDY I Wayan Sutapa; Ria Armunanto; Karna Wijaya
Indonesian Journal of Chemistry Vol 10, No 2 (2010)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (304.266 KB) | DOI: 10.22146/ijc.21458

Abstract

The dissociative chemisorption of hydrogen on both pure and Sc-incorporated Mg(0001) surfaces have been studied by ab initio density functional theory (DFT) calculation. The calculated dissociation energy of hydrogen molecule on a pure Mg(0001) surface (1.200 eV) is in good agreement with comparable theoretical studies. For the Sc-incorporated Mg(0001) surface, the activated barrier decreases to 0.780 eV due to the strong interaction between the molecular orbital of hydrogen and the d metal state of Sc. This could explain the experimentally observed improvement in absorption kinetics of hydrogen when transition metals have been introduced into the magnesium materials.
ANALYSIS OF HYDROGEN ADSORPTION AND DIFFUSION ON Mg(0001) SURFACE: AN AB INITIO DFT STUDY I Wayan Sutapa; Ria Armunanto; Karna Wijaya
Jurnal Sains dan Terapan Kimia Vol 4, No 1 (2010)
Publisher : Program Studi Kimia, Universitas Lambung Mangkurat

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (220.13 KB) | DOI: 10.20527/jstk.v4i1.2046

Abstract

Ab initio density functional theory (DFT) calculations are performed to study the adsorption of H2 molecules on a Mg(0001) surface. First, the adsorption energy was investigated. In the calculation of the adsorption process of molecular hydrogen, observation showed a physical adsorption of molecular hydrogen rather than chemisorptions.The diffusion process of atomic hydrogen on Mg (0001) was also presented. Finally, we are comparing all of our calculation with results from previous experiments. Keyword: DFT, Adsorption, Diffusion, Mg(0001), H2 
QSAR Studies of Nitrobenzothiazole Derivatives as Antimalarial Agents Hadanu, Ruslin; Adelin, La; Sutapa, I Wayan
Makara Journal of Science Vol. 22, No. 1
Publisher : UI Scholars Hub

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Quantitative Structure and Activity Relationship (QSAR) analyses were carried out for a series of 13 nitrobenzothiazole derivatives as antimalarial compounds to find out the structural relationship of their antimalarial activities against the W2 Plasmodium falciparum strain. The electronic descriptors have been determined usingthe atomic net charges (q), dipole moment (μ), ELUMO, EHOMO, polarizability (α) and Log P. Inaddition, the descriptors were calculated through Hyper Chem for Windows 8.0 using the PM3 semi-empirical method. The antimalarial activities (IC50) were taken fromliterature [1]. Furthermore, the QSAR model was determined by multiple linear regression (MLR) approach, giving equation model of QSAR: Log IC50 = 41.483 + 54.812 (qC2) – 50.058 (qS3) + 416.766 (qC4) + 440.734 (qC5) – 754.213 (qC7) – 73.721 (qC8) + 246.715 (qC9) + 0.551 (μ) – 13.269 (EHOMO) – 3.404 (ELUMO) + 0.042 (α) + 0.107 (LogP). The most statistically significant QSAR model with correlation coefficients n = 13, (r) = 1.00, (r2) = 1.00, SE = 0, and PRESS = 3.40 were developed by MLR. Based on the model of the above QSAR equation 43 new nitrobenzothiazole derivatives were modeled and 24 of these compounds showed high antimalarial activity. It isrecommended that these are synthesized for further investigation 4 new compounds (45, 49, 52 and 55) show equivalent activity to that achieved with chloroquine antimalarial drugs.
Biodiesel from the waste cooking oil is catalyzed by egg-shell of purebred chicken with methanol as a solvent Priska Marisa Pattiasina; I Wayan Sutapa; Hellna Tehubijuluw
BIOEDUPAT: Pattimura Journal of Biology and Learning Vol 3 No 1 (2023): Bioedupat : Pattimura Journal of Biology and Learning
Publisher : Program Studi Pendidikan Biologi, Pascasarjana, Universitas Pattimura

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30598/bioedupat.v3.i1.pp71-74

Abstract

The synthesis of biodiesel from the waste cooking oil was carried out using the catalyst from egg shell of purebred chicken with methanol as a solvent. Synthesis the biodiesel was prepared in two steps, there are esterification and transesterification. In esterification was conducted in mol ratio of methanol and waste cooking oil were 9:1, with H2SO4 as a catalyst. Transesterification with mol ratio methanol and waste cooking oil were 12:1, with CaO from egg shell of purebred chicken as a catalyst. CaO catalyst was yielded by calcinations egg shell of purebred chicken on 1000 ⁰C for two hours. Calcination product was characterized with X-RD to determine of CaO. Result of biodiesel was characterized based on 1H-NMR, FTIR, GC-MS, dan ASTM (American Standard Testing of Materials). Yielded of biodiesel theoretically was 40.298% and experiment was 36.779%. Main component that resulted there is methyl stearic (40.21%).
Computational Study Potency of Eugenol and Safrole Derivatives as Active Sunscreen Material Yusthinus Thobias Male; I Wayan Sutapa; Mirella Fonda Maahury; Muhamad Jamal; Dominggus Male
Molekul Vol 17 No 1 (2022)
Publisher : Universitas Jenderal Soedirman

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20884/1.jm.2022.17.1.5574

Abstract

Computational studies have been carried out on eugenol and safrole derivatives as active sunscreen materials. The calculations were using Density Functional Theory (DFT) with the B3LYP functional and basis set 6-31G (d). The calculated eugenol derivative i.e. 3,4-dimethoxy isobutyl cinnamate; 3,4-dimethoxy isoamyl cinnamate; 3,4-dimethoxy isohexyl cinnamate; 3,4 dimethoxy isoheptyl cinnamate; 3,4-dimethoxy isoctyl cinnamate. The calculated safrole i.e. 3,4-methylenedioxy isobutyl cinnamate; 3,4-methylenedioxy isoamyl cinnamate; 3,4-methylenedioxy isohexyl cinnamate; 3,4-methylenedioxy isoheptyl cinnamate; and 3,4-methylenedioxy isooctyl cinnamate. The main parameter in determining the potential of sunscreen compounds is energy gap. The results of computational calculations show that the 3,4-methylenedioxy isohexyl cinnamate has the smallest energy gap (HOMO-LUMO) of 0.15021 eV. This shows that 3,4-methylenedioxy isohexyl cinnamate has a better potential as an active sunscreen material. In addition, the elongation of the alkyl chain does not significantly affect the HOMO-LUMO energy difference
PEMANFAATAN BUAH LOKAL DALAM RANGKA PEMBUATAN MINYAK KELAPA MURNI (VCO/VIRGIN COCONUT OIL) DI DESA TIAL KABUPATEN MALUKU TENGAH A Netty Siahaya; Chaterina Bijang; Sherly J. Sekewael; I Wayan Sutapa
BAKIRA: Jurnal Pengabdian Kepada Masyarakat Vol 1 No 2 (2020): BAKIRA : Jurnal Pengabdian Kepada Masyarakat
Publisher : Lembaga Penelitian dan Pengabdian Kepada Masyarakat (LP2M) Universitas Pattimura

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30598/bakira.2020.1.2.79-83

Abstract

The community service program aims to increase the economic value of coconut fruit through the production pf the processed coconut into virgin coconut oil with the target being women. Empowerment of women families in the Tial Vilage who are economically unproductive people (ordinary people). The targets are set by considering the efficiency and intensity of program implementation. Participants who are the group of housewives with the types of problems handled include aspect of production and business management. The production aspect is by training women for family welfare empowerment to produce virgin coconut oil (VCO) without healting with the hel of enzymes sourced from the use og local fruits, namely pineaplles and papaya. Meanwile, business management is planned by cooperating with cooperatives, stalls, shops,traders in markets, and supermarkets for marketing. Inessence, this activity is expected to be a solution to the problems faced by the community through an integrated approach, in order to increase the economic value of coconuts which are still not optimally utilized.
Pemanfaatan Software Kimia Komputasi Untuk Siswa SMA Negeri 2 Seram Bagian Barat Mario Rowan Sohilait; Nelson Gaspersz; I Wayan Sutapa; Hellna Tehubijuluw; Imanuel B. D Kapelle; Rahayu Rahayu; Priska Marissa Pattiasina; Fensia Analda Souhoka; Nurani Hasanela
Innovation for Community Service Journal Vol 1 No 1 (2023): April 2023
Publisher : Department of Chemistry

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30598/icsj.v1i1.8551

Abstract

Pandemi global Covid-19 yang melanda seluruh dunia turut berdampak signifikan di bidang pendidikan. Salah satunya proses pembelajaran di tingkat SMA yang berubah dari kelas tatap muka menjadi kelas online, menyebabkan ada siswa yang kesulitan memahami pelajaran. Kurangnya pemahaman materi sebelumnya menyebabkan siswa kesulitan beradaptasi pada materi lanjutan pada saat kelas luring berlangsung, misalnya untuk pelajaran kimia. Oleh karena itu, untuk meningkatkan pengetahuan dan pemahaman siswa-siswi SMA tentang kimia, dapat dilakukan melalui pendekatan kimia komputasi. Kegiatan pengabdian masyarakat yang dilakukan bertujuan untuk menumbuhkan minat siswa-siswi SMA, sehingga lebih mengenal dan dapat mengoperasionalkan software kimia komputasi sebagai pembelajaran kimia yang menarik. Kegiatan ini dilakukan dengan metode ceramah dan praktek langsung bagi siswa-siswi. Ketua tim menyampaikan materi tentang pengantar kimia komputasi, aplikasi dan manfaat kimia komputasi dalam bidang sains, serta bagaimana pemodelan struktur molekul menggunakan program HyperChem dan Gaussian. Pada tahap praktek langsung, siswa dilatih mengoperasionalkan komputer dan memanfaatkaan software untuk mempelajari struktur molekul organik sederhana. Molekul etanol digambar oleh siswa menggunakan ChemSketch dan optimasi geometri menggunakan Hyperchem, sedangkan visualisasi molekul air menggunakan Gaussian. Setelah kegiatan pengabdian berlangsung, siswa-siswi SMA Negeri 2 Seram Bagian Barat lebih memahami konsep tentang struktur molekul dan lebih antusias ingin mempelajari kimia setelah penggunaan software kimia komputasi tersebut.
Cow's Fat Processing To Biodiesel By NaOH As Catalyst In Methanol Fransina, Eirene; Sutapa, I Wayan; Hehanussa, Susan
Indonesian Journal of Chemical Research Vol 1 No 1 (2013): Edisi Pertama (First Edition)
Publisher : Jurusan Kimia, Fakultas Sains dan Teknologi, Universitas Pattimura

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30598/ijcr.2013.1-eir

Abstract

The research about biodiesel produced from cow's fat using sodium hydroxide (NaOH) as catalyst has been done. Biodiesel produced from cow's fat was done through transesterification process using methanol 1:12 which priory react with 0.3% NaOH as catalyst due to oil and methanol weight. The transesterification process was conducted for 5 hours at 65°C. Biodiesel from cow's fat is characterisized by GC-MS and ASTM (American Society for Testing and Materials) method. Methyl ester which produced from cow's Fat fat are 31.67% of stearic acid, 25.67% of palmitate acid, and 22.68% of oleate acid. Biodisel from cow's fat are qualified as diesel fuel and biodiesel characterisized by ASTM for specific density (0.8705 kg/m3), kinematic viscosity (4,481 mm2/s), flash point (176,5 0C), pour point (21 0C), and Conradson's carbon residu (0.0139% wt).
Biodiesel Production From Bintanggur Oil (Callophyllum inophyllum L.) Using Calsium Oxide (CaO) Catalyst Sutapa, I Wayan; Rosmawaty, Rosmawaty; Samual, Ismah
Indonesian Journal of Chemical Research Vol 1 No 1 (2013): Edisi Pertama (First Edition)
Publisher : Jurusan Kimia, Fakultas Sains dan Teknologi, Universitas Pattimura

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30598/ijcr.2013.1-way

Abstract

The research of the biodiesel from bintanggur oil (Calophyllum inophyllum L.) using calsium oxide (CaO) catalyst had been done. In this study, a two-step process was used to produce biodiesel from bintanggur oil. Initially by esterification process using H2SO4 1.25% catalyst by weight of oil and methanol with a molar ratio of 1:9 and continued by transesterification process with 1:12 (oil : methanol) with the catalyst 8 wt% CaO. The esterification and the transesterification process carried out of 2 hours and 7 nespectively at a 65 °C. The synthesis of biodiesel was analyzed by FT-IR spectrophotometer. The conversion of biodiesel is 44.49%. The biodiesels properties were caracterized by ASTM method. Results of biodiesels properties there are specific gravity of 0.8878 g/cm3, viscosity kinematic 5.572 cSt, flash point 176.5 °C, pour point 9 °C, cooper strip corrosion 1b, and Conradson carbon residue 2.469%.
Adsorption Cu2+ Metal Ion Of Pectin From “Tongka Langit” Banana’s Crust (Musa Speices Van Balbisiana) Sutapa, I Wayan; Siahay, Victor P.D.; Tanasale, Matheis F.J.D.P.
Indonesian Journal of Chemical Research Vol 1 No 2 (2014): Edisi Bulan Januari (Edition For January)
Publisher : Jurusan Kimia, Fakultas Sains dan Teknologi, Universitas Pattimura

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30598/ijcr.2014.1-way

Abstract

The adsorption Cu2+ metal ion of pectin from "tongka langit" bananas crust (Musa Speices van balbisiana) has been done. Pectin was obtained from extraction "tongka langit" bananas crust with HCl at temperature 90 oC during 4 hours. Pectin was produced 9.49 grams (10.41%). Identification functional group of pectin before and after adsorption use FT-IR spectrophotometer and defractometer XRD while Cu2+ metal adsorption result was analized with using AAS. Adsorption Cu2+ metal was followed adsorption isotherm Freundlich with KF value = 4.33 mg/g and n value = 0.86.