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Indonesian Journal of Chemistry

ijc
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Published by Universitas Gadjah Mada

ISSN : 14119420 EISSN : 24601578 DOI : -

Core Subject : Science, Engineering,

Chemical Engineering, Chemistry & Bioengineering Chemistry

Indonesian Journal of Chemistry is an International, peer-reviewed, open access journal that publishes original research articles, review articles, as well as short communication in all areas of chemistry including applied chemistry. The journal is accredited by The Ministry of Research, Technology and Higher Education (RISTEKDIKTI) No : 21/E/KPT/2018 (in First Rank) and indexed in Scopus since 2012. Since 2018 (Volume 18), Indonesian Journal of Chemistry publish four issues (numbers) annually (February, May, August and November).

Arjuna Subject : -

Articles 1,981 Documents

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MONTE CARLO SIMULATIONS OF Co (II) IN WATER INCLUDING THREE-BODY CORRECTION Cahyorini Kusumawardani; Harno Dwi Pranowo; Crys Fajar Partana; Mudasir Mudasir
Indonesian Journal of Chemistry Vol 6, No 3 (2006)
Publisher : Universitas Gadjah Mada

In order to describe the cobalt-water interaction correctly, a new ab initio potential was developed consisting of pair interaction terms as well as three-body contributions. Within this approach, it was possible to correct for the well-known failures of pair potentials in describing solvation phenomena of such ions. A first-shell coordination number of 6 in agreement with experimental data were obtained from Monte Carlo simulations of a single cobalt (II) ion in water. The structure of hydrated ion is discussed in terms of radial density functions and coordination number, energy and angular distributions.

PREPARATION OF MESOPOROUS TITANIA-SILICA AEROGELS BY CO2 SUPERCRITICAL EXTRACTION Silvester Tursiloadi; Dinie Mansur; Yeny Meliana; Ruslan Efendi
Indonesian Journal of Chemistry Vol 7, No 2 (2007)
Publisher : Universitas Gadjah Mada

Stable anatase is attractive because of its notable functions for photocatalysis and photon-electron transfer. TiO2-nanoparticles dispersed SiO2 wet gels were prepared by hydrolysis of Ti(OC4H9n)4 and Si(OC2H5)4 in a 2-propanol solution with acid catalyst. The solvent in the wet gels was supercritically extracted using CO2 at 60 oC and 22 Mpa in one-step. Thermal evolution of the microstructure of the extracted gels (aerogels) was evaluated by XRD measurements, TEM and N2 adsorption measurements. The as-extracted aerogel with a large specific surface area, more than 365 m2g-1, contained anatase nanoparticles, about 5 nm in diameter. The anatase phase was stable after calcinations at temperatures up to 1000 oC, and BET specific surface area, total pore volume and average pore diameter did not change significantly after calcinations at temperature up to 800 oC.

CONFORMATIONAL STUDIES OF LIGNANS FROM Durio oxleyanus Griff. (Bombacaceae) Rudiyansyah Rudiyansyah; Lynette K Lambert; Mary J Garson
Indonesian Journal of Chemistry Vol 10, No 1 (2010)
Publisher : Universitas Gadjah Mada

Searching for secondary metabolites from the wood bark of Durio oxleyanus has afforded two new lignans, namely threo-carolignan Y (1) and erythro-carolignan Y (2) together with three other known lignans erythro-carolignan X (3), boehmenan X (4) and boehmenan (5). The relative configurations of compounds 1 and 2 were established by J-based configurational analysis and 2D NOESY studies.

BIOACTIVITY AND CLONING OF A NEW ANTIBACTERIAL LECTIN PROTEIN IN SPONGE Gelliodes sp. FROM BARANGLOMPO ISLAND IN SOUTH SULAWESI INDONESIA TERRESTRIAL Hanapi Usman; Prastawa Budi; Ahyar Ahmad
Indonesian Journal of Chemistry Vol 10, No 2 (2010)
Publisher : Universitas Gadjah Mada

A research on antibacterial bioactivity of protein fraction isolated from several species of sponges of Barang Lompo Island has been conducted. Pre-purification of protein using fractional method, showed maximum bioactivity with the inhibition zone of 26 mm to Salmonella typhy from sponge Gelliodes sp. with the saturation level of ammonium sulfate of 40-60%. Further purification of this fraction using column chromatography followed by protein sequencing, indicated that pure protein as lectin, and behaves as a single-band on SDS-PAGE with molecular weight of 21 kDa. Based on amino acids partial sequence, we cloned and sequencedcDNA encoding lectin protein.It consists of 552 nucleotides encoding 183 amino acid residues including a putative initiationMet. To obtain it in large amounts, the coding sequence of lectin was cloned into pGEX-2TK vector and expression as a lectin fusion protein in Escherichia coli. Recombinant lectin exhibited a similar antibacterial activity to the native lectin. The recombinant lectin had stronger antibacterial activity toward S. typhy and S. aureus (G+) with the diameters of inhibition zone were 16 mm and 17 mm, respectively. This research might provide significant results for the following research on the antibacterial action in molecular level of lectin protein from marine sponges.

EFFECT OF Cr(VI) IONS ON THE EFFECTIVENESS OF CHLOROPHENOL PHOTODEGRADATION Endang Tri Wahyuni; Ngatidjo Hadipranoto; Iqmal Tahir; Bambang Haryo Gatut Tamtama
Indonesian Journal of Chemistry Vol 4, No 3 (2004)
Publisher : Universitas Gadjah Mada

In order to solve environmental problems due to chlorophenol compound and which is hazardous and carcinogenic, the effect of Cr(VI) ions on the chlorophenol photodegradation effectiveness has been evaluated. Photodegradation process was carried out in a closed reactor by batch sistem, by exposing the UV lamp into a solution containing chlorophenol and Cr(VI) ions for a period of time. Then the solution was analyzed by gas chromatography for determination of the residual chlorophenol concentration. In this research, the influences of reaction time, Cr(VI) ions concentration, and solution pH on the photodegradation results were also evaluated. The research results indicated that the effectiveness of the photodegradation increases when ion Cr(VI) was added. The improvement of the effectiveness is proportional with the increase of the concentration of Cr(VI) added. The effectiveness of the photodegradation is also influenced by solution pH, and the highest is reached at pH < 2. Chlorophenol photodegradation follows first order reaction. The respective rate reaction constants for chlorophenol photodegradation in the absence and in the presence of Cr(VI) ions are 4.91x 10-2 and 11.41x 10-2 hours-1

MISCONCEPTION REMEDIATION OF ATOMIC ORBITAL, MOLECULAR ORBITAL, AND HIBRIDIZIATION CONCEPTS BY COMPUTER ASISSTED INSTRUCTION WITH ANIMATION AND SIMULATION MODEL Sri Mursiti; Dewi Selvia Fardhyanti; Edy Cahyono; Sudarmin Sudarmin
Indonesian Journal of Chemistry Vol 6, No 1 (2006)
Publisher : Universitas Gadjah Mada

The research of Computer Asissted Instruction with animation and simulation was used to misconception remediation of atomic orbital, molecular orbital, and hibridiziation concepts. The applicated instruction model was focused on concept approach with macromedia flash player and power point programme. The subject of this research were the 2nd semestre students of Chemistry Department. The data were collected by using of true-false pre-test and post- test followed by the reason of its. The analysis reveals that the Computer Asissted Instruction with animation and simulation model increased the understanding of atomic orbital, molecular orbital, and hibridiziation concepts or remediation of concepts missconception, shown by the significant score gained between before and after the implementation of Computer Asissted Instruction with animation and simulation model. The instruction model developed the students's generic skills too.

SO2 EMISSION MEASUREMENT BY DOAS (DIFFERENTIAL OPTICAL ABSORPTION SPECTROSCOPY) AND COSPEC (CORRELATION SPECTROSCOPY) AT MERAPI VOLCANO (INDONESIA) Hanik Humaida
Indonesian Journal of Chemistry Vol 8, No 2 (2008)
Publisher : Universitas Gadjah Mada

The SO2 is one of the volcanic gases that can use as indicator of volcano activity. Commonly, SO2 emission is measured by COSPEC (Correlation Spectroscopy). This equipment has several disadvantages; such as heavy, big in size, difficulty in finding spare part, and expensive. DOAS (Differential Optical Absorption Spectroscopy) is a new method for SO2 emission measurement that has advantages compares to the COSPEC. Recently, this method has been developed. The SO2 gas emission measurement of Gunung Merapi by DOAS has been carried out at Kaliadem, and also by COSPEC method as comparation. The differences of the measurement result of both methods are not significant. However, the differences of minimum and maximum result of DOAS method are smaller than that of the COSPEC. It has range between 51 ton/day and 87 ton/day for DOAS and 87 ton/day and 201 ton/day for COSPEC. The measurement of SO2 gas emission evaluated with the seismicity data especially the rockfall showed the presence of the positive correlation. It may cause the gas pressure in the subsurface influencing instability of 2006 eruption lava.

HIGH PERFORMANCE THIN LAYER CHROMATOGRAPHIC DETERMINATION OF CAFFEIC ACID AND ROSMARINIC ACID FROM THE LEAVES OF Orthosiphon stamineus M. Amzad Hossain; Zhari Ismail
Indonesian Journal of Chemistry Vol 9, No 1 (2009)
Publisher : Universitas Gadjah Mada

This paper presents the studies performed on extraction of Orthosiphon stamineus, Benth by using different solvent for the identification and quantification of the caffeic acid derivatives such as caffeic acid and rosmarinic acid which confers to the leaves of this plant with remarkable pharmaceutical properties. High performance thin-layer chromatographic (HPTLC) allows the identification and the quantification of more than 20 samples in the same chromatographic run. The analysis of the samples requires 15-30 min compared with more than 2 h using a typical HPLC method. Using the techniques of the HPTLC and the UV-VIS spectra we have found that the extraction of this herb plant contain, the caffeic acid and rosmarinic acid ranging between 0.029% up to 0.506% and up to 0.24% to 2.24% respectively.

A THERMOPHILIC MICROBE PRODUCING DEXTRANASE FROM HEATED SUGAR CANE Afaf Baktir; Zumrotul Koiriyah; Ali Rohman
Indonesian Journal of Chemistry Vol 5, No 3 (2005)
Publisher : Universitas Gadjah Mada

A thermophilic aerobe microorganism designated NP4, was isolated from the heated sugar cane. It grew on dextran, and produced a thermoactive extracellular dextranase. Screening and isolation was done by assay of dextranase activity semi quantitatively on solid medium containing blue dextran. It provided several colonies with different morphology exhibited decolourized zones around, on culture plates containing blue dextran 2000R. The screening resulted in isolation of one microbe which efficiently assimilate dextran as carbon source. Dextranase production from the choised strain in liquid medium was conducted at room temperature for 8 hours with shaking speed of 125 rpm. The dextranase enzyme showed optimum pH of 8 and optimum temperature of 60 oC.

GROWTH RATE DISTRIBUTION OF BORAX SINGLE CRYSTALS ON THE (001) FACE UNDER VARIOUS FLOW RATES Suharso Suharso
Indonesian Journal of Chemistry Vol 6, No 1 (2006)
Publisher : Universitas Gadjah Mada

The growth rates of borax single crystals from aqueous solutions at various flow rates in the (001) direction were measured using in situ cell method. From the growth rate data obtained, the growth rate distribution of borax crystals was investigated using Minitab Software and SPSS Software at relative supersaturation of 0807 and temperature of 25 °C. The result shows that normal, gamma, and log-normal distribution give a reasonably good fit to GRD. However, there is no correlation between growth rate distribution and flow rate of solution.

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