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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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Recycling Mimeograph-Printed Newsprint Paper E. L Mari; A.S Torres; C.O Austria
ASEAN Journal on Science and Technology for Development Vol. 28 No. 2 (2011): ASEAN Journal on Science and Technology for Development (AJSTD)
Publisher : Universitas Gadjah Mada

Virgin newsprint paper from thermo-mechanical pulp was subjected to a laboratory recycling scheme, which involved mimeograph-printing, re-pulping, de-inking, washing, refining, and handsheetforming, without adding other fibre in between cycles. Fibre dimension, pulp freeness and paper properties were determined after each cycle until the fifth, at which about 20% of the original material remained. The remaining fibre was then mixed with virgin pulp, the original newsprint and unsorted mixed office waste to determine the proportion necessary for acceptable properties. The results indicated remarkable modification in distribution of fibre properties, a decreasing amount of long fibre with corresponding increase of short fibre in the course of recycling and loss of fibre. Refining generally improved the strength properties of paper from recycled fibre. About 20 % to 30 % of either thermo-mechanical pulp or unsorted mixed office waste was found sufficient for blending with recycled fibre to obtain acceptable strength properties.

Performance Evaluation of a UASB Reactor Using Dairy Wastes A Ali; S Khan; K.A Khan
ASEAN Journal on Science and Technology for Development Vol. 29 No. 1 (2012): ASEAN Journal on Science and Technology for Development (AJSTD)
Publisher : Universitas Gadjah Mada

A UASB reactor of 6-litre capacity, made of acryl material, was operated continuously for 20–22 weeks in three different phases, using actual dairy mill effluent at a constant mesophilic temperature and neutral pH. The dairy wastewater was highly alkaline, turbid and milky in colour with a bad odour. The average COD and BOD concentrations of the dairy mill effluent were observed to be 2945 mg/l and 1070 mg/l, respectively. Phase I was the start-up phase, with OLR of 0.13 g COD/l.d. SLR, effluent VFAs, effluent TSS, biogas production and methane composition observed during this phase were 1.4 g COD/g VSS.d, 1240 mg/l, 240 mg/l, 1.74 l/CODrem.d, and 62%, respectively. The overall observed biomass yield was found to be equal to 0.034 g VSS/g CODrem. During phase II,the optimum pH was determined to be 6.8–7.1. In the last phase, phase III, the effects of OLR and HRT were observed. The optimum OLR and HRT were observed to be 4.76 g COD/l.d and 16 h, respectively. Correspondingly the COD removal efficiency, effluent VFA and TSS concentrations, and the amount of biogas production were observed to be 78%, 770 mg/l, 300 mg/l and 2.07 l/CODrem.d, respectively. The results of this study suggest that a UASB reactor is an effective tool and viable option for reducing pollution from dairy mill effluent.

Bond Strength of Glued-in Rods in Malaysian Tropical Timber as Influenced by Adhesive, Diameter and Glueline Thickness N.E.L Za'ba; Z Ahmad; A Ibrahim
ASEAN Journal on Science and Technology for Development Vol. 29 No. 1 (2012): ASEAN Journal on Science and Technology for Development (AJSTD)
Publisher : Universitas Gadjah Mada

Failure in wood structure is mainly caused by improper connection design, construction (fabrication) details, or serviceability. Besides using traditional bolting methods such as nails, screws and bolts to join members, timber members also can be connected by using bonded-in joints. However, current knowledge in the use of this type of timber connection is still limited. This study investigated the performance of bonded-in pultruded rods in timber as connections by exploring the effect of a few parameters such as rod type, diameter of the rod, adhesive type and thickness of the glueline. Pull-out tests were used to characterize the strength of the bonded-in connections. From the results of this study, it was found that strength increased as glueline thickness increased, while strength decreasedas the diameter of the rod increased.

Design and Construction of Automized Assembly Application E.E HTWE; S Hatanaka; T Akiyama
ASEAN Journal on Science and Technology for Development Vol. 29 No. 1 (2012): ASEAN Journal on Science and Technology for Development (AJSTD)
Publisher : Universitas Gadjah Mada

Nowadays the main stream of current automatic process and assembly is on intermittent transportation. Robot control systems can be divided into motion control and force control depending on the work. Assembly work is necessary to consider the state of force applied by detection of the force or moment on the fingers of the gripper. In this project, four groups designed and developed each one of the stages of the workpieces until the final piece was delivered; it was composed of three different workpieces. The mechanism was designed to set the shaft and fasten the screw into a vacancy in a workpiece. The machine was constructed with frame, base plate, support, gripper and workpieces by using CNC milling, turning, drilling and wirecut machine. This paper briefly describes the design analysis of a conveyor, actuator and motor control system.

Implementation of a Communication Satellite Orbit Controller Design Using State Space Techniques M.T HLA; Y.M Lae; S.L Kyaw; M.N Zaw
ASEAN Journal on Science and Technology for Development Vol. 29 No. 1 (2012): ASEAN Journal on Science and Technology for Development (AJSTD)
Publisher : Universitas Gadjah Mada

This research is of great importance for controlling the altitude of a satellite, especially one used for global communications in a geo-stationary orbit. The objective of this research was to advance a design based on the modelling of an orbit controller for a satellite orbiting into a circular orbit. This encompasses a good understanding of the system’s dynamics. Once a satellite is launchedinto a desired orbit, it never remains in this ideal orbit. The external forces present in space cause perturbations to the ideal orbit. To bring the satellite back into the desired orbit, on-board thrusters provide the in-orbit propulsion. In this research, the altitude of the satellite was controlled by a thruster fashioned by the on-board thrusters installed in the radial and tangential directions. However,dictated by the controllable prerequisite, we achieved dynamic system stabilization with the aid of two thrusters as well as one thruster. Thus, the feedback dynamic control system responded to both the two-input and the single-input cases. The model developed was effectively a linearized, normalizedand state-space model. The simulation of this model was based on the MATLAB environment. The design evolved accordingly was used to revise the effect of pole placement on the controlling parameters, such as settling time, peak time, overshoot, and damping ratio of the closed-loop system. This enabled us to make predictions on the stability requirements for several dynamic systems ofthe type considered. The design tool thus developed was applied to an actual current communication satellite design. The design results were evaluated and recommendations completed.

Ferromagnetic Order in the Intermetallic Alloys laNi5-xMgx D.N Ba; L.T Tai; N.T Trung; N.T Huy
ASEAN Journal on Science and Technology for Development Vol. 29 No. 1 (2012): ASEAN Journal on Science and Technology for Development (AJSTD)
Publisher : Universitas Gadjah Mada

The influences of the substitution of Ni with Mg on crystallographic and magnetic properties of the intermetallic alloys LaNi5-xMgx (x ? 0.4) were investigated. The X-ray diffraction patterns showed that all samples were of single phase, and the lattice parameters, a and c, decreased slightly upon chemical doping. LaNi5 is well known as an exchange-enhanced Pauli paramagnet. Interestingly, in LaNi5-xMgx, the ferromagnetic order existed even with a small amount of dopants; the Curie temperature reached the value of room temperature for x = 0.2, and enhanced with increasing x.

Nanoherbals in Human Healthcare: A Proposed Research and Development Roadmap I S Ahmad; U Hashim
ASEAN Journal on Science and Technology for Development Vol. 29 No. 1 (2012): ASEAN Journal on Science and Technology for Development (AJSTD)
Publisher : Universitas Gadjah Mada

Bioactive secondary metabolites derived from herbs are examined for their suitability of conversion into nanoforms having flexible morphological controls, surface stabilizations and surface functionalization. This can lead to stable chemical conjugations based on molecular recognition for their possible applications in the form of smart pharmaceuticals, nutraceuticals, cosmaceuticals and many other related areas of human healthcare using green chemistry routes. Using the principles of nanoscience and technology in association with genomics and proteomics, an attempt has been made to decipher whether a suitable form of drug discovery and targeted drug delivery like schemes arefeasible in case of such nano phytochemicals using various kinds of nanosize carriers and labelling molecules already identified in the course of investigations of contemporary single molecule drug developments. Additional efforts can clarify whether such species will be successful in the early detection of diseases based on marker molecules. Once identified, these green phytochemicals will certainly replace many hazardous chemical compounds by their environmentally friendly and sustainable forms in times to come.

Nanoherbals in Human Healthcare: A Proposed Research and Development Roadmap II S Ahmad; U Hashim
ASEAN Journal on Science and Technology for Development Vol. 29 No. 1 (2012): ASEAN Journal on Science and Technology for Development (AJSTD)
Publisher : Universitas Gadjah Mada

Bioactive secondary metabolites derived from herbs are examined for their suitability of conversion into nanoforms having flexible morphological controls, surface stabilizations and surface functionalization. This can lead to stable chemical conjugations based on molecular recognition for their possible applications in the form of smart pharmaceuticals, nutraceuticals, cosmaceuticals and many other related areas of human healthcare using green chemistry routes. Using the principles of nanoscience and technology in association with genomics and proteomics, an attempt has been made to decipher whether a suitable form of drug discovery and targeted drug delivery like schemes are feasible in case of such nano phytochemicals using various kinds of nanosize carriers and labelling molecules already identified in the course of investigations of contemporary single molecule drug developments. Additional efforts can clarify whether such species will be successful in the early detection of diseases based on marker molecules. Once identified, these green phytochemicals will certainly replace many hazardous chemical compounds by their environmentally friendly and sustainable forms in times to come.

Performance of Jatropha Oil-based Biodiesel Fuel in a Single-cylinder Four-Stroke Diesel Engine H.H Win
ASEAN Journal on Science and Technology for Development Vol. 29 No. 2 (2012): ASEAN Journal on Science and Technology for Development (AJSTD)
Publisher : Universitas Gadjah Mada

Studies on alternative fuels have been active in Myanmar because the rapid mechanization of the agricultural sector demands higher diesel consumption. Jatropha oil-based biodiesel is one of the potential alternatives because of the relative ease of growing and producing this plant. In this study, both the experimental and theoretical analyses of Jatropha oil-based B20 biodiesel wereperformed and compared with conventional diesel. First, B20 was prepared by the base-catalyzed transesterification of the oil and its properties were measured. Second, separate performance tests were conducted on diesel and the biodiesel fuel using a LEYER-16 diesel engine. The speed range of interest was between 1000 r.p.m and 2000 r.p.m. Third, performance simulations were done in MATLAB using an algorithm written based on the theory of the engine operating cycle and air/ fuel compositions. Both experimental and simulation results show that there were no significant differences in the brake power and thermal efficiency of the engine between using diesel and the B20 diesel. However, fuel consumption when using B20 was slightly higher than that of diesel. This difference was marginal and it can be concluded that engine performance characteristics are the same for both diesel and B20 suggesting that B20 has great potential to be used as a substitute for diesel.

Developing a Generalized Combined Model for Gas-liquid Two-phase Flow Pressure Drop in Elbow Bends N.Z Aung; T Yuwono
ASEAN Journal on Science and Technology for Development Vol. 29 No. 2 (2012): ASEAN Journal on Science and Technology for Development (AJSTD)
Publisher : Universitas Gadjah Mada

In this work, a generalized combined model was proposed for prediction of two-phase flow pressure drop in elbow bends. In this proposed model, restriction, frictional and elevational losses were considered separately. The frictional and static losses were approached by using Lockhart_Martinelli correlation. This model was tested to predict the pressure drop across the elbows with inside diameter of 0.036 m and R/D = 0.6, 2.5. The superficial liquid velocity was varied in the range of0.3~1.1 m/s and volumetric gas quality was varied from 0.02~0.3. The results from this model had good predictions with a maximum error of ±13% for long elbow bends and showed great discrepancy with a peak error of –50% for short elbow bends. The model is reliably acceptable for the elbow bends with relative radius (R/D) greater than 2 at volumetric gas fractions less than 0.3.

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