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ASEAN Journal on Science and Technology for Development

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Published by Universitas Gadjah Mada

ISSN : 22249028 EISSN : 22249028 DOI : -

Core Subject : Science, Education, Engineering,

Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Computer Science & IT Mathematics

The coverage is focused on, but not limited to, the main areas of activity of ASEAN COST, namely: Biotechnology, Non-Conventional Energy Research, Materials Science and Technology, Marine Sciences, Meteorology and Geophysics, Food Science and Technology, Microelectronics and Information Technology, Space Applications, and Science and Technology Policy, Infrastructure and Resources Development.

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Articles 477 Documents

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EFFECT OF INJECTOR OPENING PRESSURE ON PERFORMANCE AND EMISSION OF LPG - METHYL ESTER OF MAHUA OIL DUAL FUEL ENGINE N. Kapilan
ASEAN Journal on Science and Technology for Development Vol. 25 No. 2 (2008): ASEAN Journal on Science and Technology for Development (AJSTD)
Publisher : Universitas Gadjah Mada

One of variables, which affect the performance and emission of dual fuel engine is injection pressure. Hence in the present work, effect of Injector opening pressure on the performance of the engine was studied. A four stroke single cylinder engine was modified to work in dual fuel mode. Three injector opening pressures (180 bar, 200 bar and 220 bar) were considered for the present work. Methyl ester of mahua oil was used as pilot fuel and LPG was used as primary fuel. From the test results, it was observed that the injector opening pressure of 200 bar results in higher brake thermal efficiency. The higher injector opening pressure results in better atomization and peneatration of methyl ester of mahua oil. The exhaust emissions such as Smoke, unburnt hydro carbon and carbon monoxide of 200 bar is lower than other pressures.

POTASSIUM PERMANGANATE AS OXIDANT IN THE COD TEST FOR SALINE WATER SAMPLES Chin-Ping Goh; Poh-Eng Lim
ASEAN Journal on Science and Technology for Development Vol. 25 No. 2 (2008): ASEAN Journal on Science and Technology for Development (AJSTD)
Publisher : Universitas Gadjah Mada

The objective of this study is to investigate the feasibility of applying potassium permanganate (KMnO4) as the oxidant in the COD test for highly saline water samples. Initially, the COD values of various glucose standard solutions were determined by three methods, namely the standard closed reflux dichromate (CODCr), the acidic permanganate (CODMn) and the alkaline permanganate (CODOH) methods. The results showed that at COD values lower than 20 mg/L, the standard dichromate method was not applicable due to its poor precision (RSD > 10%). The CODOH method was less effective compared to the CODMn method as the recoveries were 0.71 and 0.89, respectively. The determination of CODOH for the standard solutions of glucose in the presence of Cl- and Br-, respectively, or both Cl- and Br- ions were conducted. The results showed that the COD values only increased 5.1% with the increase in chloride concentrations up to 35000 mg Cl-/L. This shows that the CODOHmethod is a suitable method for determining the COD of highly saline water samples such as estuarine and coastal waters. The COD test was conducted for river, estuarine and coastal water samples. The results indicated that the CODOH test correlates well with the CODCr test (R2 > 0.98). The results also indicated that this CODOH test can be applied in determining the pollution trends for estuarine and coastal waters.

STRUCTURAL CHARACTERIZATION OF AGAR EXTRACTED FROM SIX RED SEAWEED SPECIES GROWING IN THE COAST OF VIETNAM Tran Thi Thanh Van; Bui Minh Ly; Ngo Quoc Buu; Chu Dinh Kinh
ASEAN Journal on Science and Technology for Development Vol. 25 No. 2 (2008): ASEAN Journal on Science and Technology for Development (AJSTD)
Publisher : Universitas Gadjah Mada

Polysaccharides extracted from six red seaweed species growing in Vietnam have been studied. Characterisation of their structure by chemical and spectroscopic methods showed that all of them have a basic repeating structure of alternating 3-linked b-D-galactopyranosyl and 4-linked 3,6-anhydro a-L-galactopyranosyl units with substituted methyl ether groups. The native agar offers only weak gelling abilities owing to the 4-linked a-L-galactopyranosyl 6-sulfate as its precursor. Conversion of this unit into the corresponding 3,6-anhydride by treating with hot alkali generally led to gel strength increasing. The agars from G. fisheri and G. firma are poorly substituted, while those from G.asiatica, G.tenustipitata and G. heteroclada are partly methylated on position 6 of the 3-linked b-D- galactose. Agar from Gelidiella acerosa is partlly methylated on both positions 6 and 2 of the 4linked 3,6-anhydro a-L-galactose. The alkali- modified agars have been obtained in acceptable quantities with gel strength of 300932 g/cm2. The obtained results showed that all the six algal species are suitable as raw material for commercial agar production and worthy of further cultivation

TEMPORO-SPECTRAL COHERENT STRUCTURE OF TURBULENCE AND PRESSURE USING FOURIER AND WAVELET TRANSFORMS Thai-Hoa Le; Dong-Anh Nguyen
ASEAN Journal on Science and Technology for Development Vol. 25 No. 2 (2008): ASEAN Journal on Science and Technology for Development (AJSTD)
Publisher : Universitas Gadjah Mada

Studying the spatial distribution in coherent fields such as turbulent and turbulent-induced force ones is important to model and evaluate turbulent-induced forces and response of structures on the turbulent flows. Turbulent field-based coherent function is commonly used for the spatial distribution characteristic of induced forces in the frequency domain. This paper will focus to study spectral coherent structure of turbulence and forces in not only the frequency domain using conventional Fourier transform-based coherence, but also temporo-spectral coherent one in the time-frequency plane thanks to wavelet transform-based coherence for more understanding of the turbulence and force coherences and their spatial distributions. Effects of spanwise separations, bluff body flow and flow conditions on coherent structures of turbulence and induced pressure, comparison between turbulence and pressure coherences as well as intermittency of coherent structure in the time-frequency plane will be investigated here.

DIBUTYLTIN(IV) ALKYLCYCLOHEXYLDITHIOCARBAMATES: SPECTROSCOPIC CHARACTERIZATION AND CRYSTAL STRUCTURES OF DIBUTYLTIN(IV) N-METHYL AND N-ETHYLCYCLOHEXYLDITHIOCARBAMATE Normah Awang; Ibrahim Baba; Y. Farina Abd. Aziz; Bohari M. Yamin
ASEAN Journal on Science and Technology for Development Vol. 25 No. 2 (2008): ASEAN Journal on Science and Technology for Development (AJSTD)
Publisher : Universitas Gadjah Mada

A new series of dibutyltin(IV) alkylcyclohexyldithiocarbamates of the type (C4H9)2Sn[S2CNR(C6H11)]2 (R = CH3, C2H5, i-C3H7) have been successfully synthesized using in-situ method. These compounds were characterized by elemental analysis, infrared and 13C NMR spectroscopy. A single crystal X-ray analysis of dibutyltin(IV) ethylcyclohexyldithiocarbamate, (C4H9)2Sn[S2CN(C2H5)(C6H11)]2 (compound 2) showed that the system of this crystal is triclinic with space group P-1 while dibutyltin(IV) methylcyclohexyldithiocarbamate, (C4H9)2Sn[S2CN(CH3)(C6H11)]2 (compound 1) has monoclinic system and it’s space group is P21/c. In the crystal structure of compound 2, the dithiocarbamate ligands are bidentically chelated to the tin atom with non-equivalent of the Sn-S distances: Sn(1)-S(1) = 2.9255(11) and Sn(1)-S(2) = 2.5419(10); Sn(1)-S(3) = 2.8922(9) and Sn(1)-S(4) = 2.5293(10) Å while in compound 1, the dithiocarbamate ligands were anisobidentically chelated to the tin atom.

CHARACTERIZATION OF ALGINATE PREPARED FROM BROWN SEAWEEDS IN THUA THIEN-HUE PROVINCE, VIETNAM Tran Vinh Thien; Chu Dinh Kinh; Tran Thai Hoa; Dinh Quang Khieu
ASEAN Journal on Science and Technology for Development Vol. 25 No. 2 (2008): ASEAN Journal on Science and Technology for Development (AJSTD)
Publisher : Universitas Gadjah Mada

The characterization of alginate prepared from brown seaweeds in TT-Hue province of Vietnam was investigated. Composition and the sequential structure of alginate were determined by 1HNMR, 13C-NMR, TOCSY, 1H-1H COSY, and 1H-13C-HSQC spectrum. It is found that alginate with molecular weight around 101 KDa is composed of homopolymeric regions of M and G blocks, interspersed with very small amount of regions of alternating structure of MG block. This information is essential for application guideline of alginate in TT-Hue province.

CLASSIFICATION AND ZONING OF WATER QUALITY FOR THREE MAIN RIVERS IN BINH TRI THIEN REGION (CENTRAL VIETNAM) BASED ON WATER QUALITY INDEX Nguyen Van Hop; Thuy Chau To; Truong Quy Tung
ASEAN Journal on Science and Technology for Development Vol. 25 No. 2 (2008): ASEAN Journal on Science and Technology for Development (AJSTD)
Publisher : Universitas Gadjah Mada

Huong, Thach Han and Kien Giang rivers are the important surface water sources in Thua ThienHue, Quang Tri and Quang Binh provinces, respectively (in Central Vietnam). The river water samples were taken monthly (from June 2001 to May 2002 for Kien Giang river and from January to December of 2004 for Thach Han and Huong rivers) at selected sites. The temperature, pH, conductivity (EC), salinity, turbidity (TUR), DO, COD, BOD5, nitrate, ammonia, phosphate, total solids (TS), hardness, total dissolved iron, total coliform (TC), fecal coliform (FC) and sodium adsorption ratio (SAR) of water samples were analyzed. Water quality index developed by Bhargava (Bhargava-WQI) was modified and applied to assess water quality of the above mentioned rivers. Based on Bhargava-WQI, the classification and zoning of the rivers for beneficial uses were carried out. The results obtained show that the water quality index can be used as an efficient tool for the water quality management and water pollution control of the rivers.

APPLICATION OF NMR IN THE INVESTIGATION OF DYNAMIC TAUTOMERISM OF 4(3H)-QUINAZOLINONE SYSTEM Pham Thi Thanh My; Chu Dinh Kinh; Thanh Thi Thu Thuy; Nguyen Ngoc Vinh; Nguyen Thi Phuong Chi
ASEAN Journal on Science and Technology for Development Vol. 25 No. 2 (2008): ASEAN Journal on Science and Technology for Development (AJSTD)
Publisher : Universitas Gadjah Mada

Tautomerism of 4(3H)-quinazolinone system with [(2-hydroxyphenyl)methylene]-2-(4oxoquinazolin-3(4H)-yl)acetohydrazide and N’-[(1E)-(4-hydroxy-3-methoxyphenyl)methylene]-2-(4-oxoquinazolin-3(4H)-yl)acetohydrazide as two representative compounds was investigated on the basis of 1H NMR method at coalescence with the help of line formprogramme. The dynamic parameters such as k, Ea, DG*, DH*, DS* were fully calculated with high reliability.

SOIL-STRUCTURE INTERACTION ANALYSES OF PILE SUPPORTED BUILDING FRAME H.S. Chore; R.K. Ingle
ASEAN Journal on Science and Technology for Development Vol. 25 No. 2 (2008): ASEAN Journal on Science and Technology for Development (AJSTD)
Publisher : Universitas Gadjah Mada

The effect of the soil-structure interaction on the simple single storeyed and two bayed space frame resting on pile group of two piles with flexible cap is examined in this paper by resorting to more rational approach and realistic assumptions. Initially, 3-D FEA is carried out independently for the frame on the premised of fixed column bases. Later, pile foundation is worked out separately. The stiffness so obtained for foundation is used in the interactive analysis of frame to quantify the effect of soil- structure interaction on the response of the superstructure. For modeling the foundation system two approaches of finite element analysis are used. In the first approach complete three dimensional finite element analysis is resorted to wherein pile, pile cap along with the soil are discretized into 20 noded isoparametric continnum elements and interface between pile and soil is idealized as 6 noded isoparametric interface elements. In the second approach simplified finite element analysis procedure is used wherein beam element, plate element and spring elements are used to model pile, pile cap and soil respectively. The salient feature of the investigation is that the interaction between pile cap and soil underlying it is considered. In the parametric study presented here, effect of pile spacing and pile configuration is evaluated on the response of superstructure in the form top displacement in frame and bending moment at top as well as bottom of the superstructure columns. Results obtained by either analysis are compared.

PRINCIPAL STRESSES IN NON-LINEAR ANALYSIS OF BAKUN CONCRETE FACED ROCKFILL DAM Mohd Hilton Ahmad; Jamaloddin Noorzaie; Fayda Al Qbadi
ASEAN Journal on Science and Technology for Development Vol. 25 No. 2 (2008): ASEAN Journal on Science and Technology for Development (AJSTD)
Publisher : Universitas Gadjah Mada

With rapid population growth and accelerating economic development, much of the world’s WATER which requires urgent attention to ensure sustainable use. Nowadays, Concrete Faced Rockfill Dam (CFRD) is preferred among dam consultant due to its advantages. They are designed to withstand all applied loads; namely gravity load due to its massive weight and hydrostatic load due to water thrust from the reservoir. Bakun CFRD, which ranks as the second highest CFRD in the world when completed, is analyzed to its safety due to both loads mentioned earlier by using Finite Element Method. 2-D plane strain finite element analysis of non-linear Duncan-Chang hyperbolic Model which formulated by Duncan and Chang is used to study the structural response of the dam in respect to the deformation and stresses of Main dam of Bakun’s CFRD project. Dead-Birth-Ghost element technique was used to simulate sequences of construction of the dam as well as during reservoir fillings. The comparison of rigid and flexible foundation on the behaviour of the dam was discussed. The maximum and minimum principal stresses are the maximum and minimum possible values of the normal stresses. The maximum principal stress controls brittle fracture. In the finite element modeling the concrete slab on the upstream was represented through six-noded element, while the interface characteristic between dam body and concrete slab was modeled using interface element. The maximum settlement and stresses of the cross section was founded and the distribution of them were discussed and tabulated in form of contours.

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