Design Of A Hvdc-Based Controller For Load Change Compensation And Stabilization Of Inter-Area Oscillations,
2017
Universiti Brunei Darussalam
Design Of A Hvdc-Based Controller For Load Change Compensation And Stabilization Of Inter-Area Oscillations, Ngamroo I.
ASEAN Journal on Science and Technology for Development
As an interconnected power system via a High-Voltage Direct Current (HVDC) link is subjected to a rapid load change with the frequency of inter-area oscillation mode, system frequency and tie line power may be severely disturbed and oscillate. To compensate for the rapid load change and stabilize both frequency and tie line power oscillations due to the inter-area mode, the dynamic power flow control via a HVDC link can be exploited. To implement this concept, a new design method of HVDC-based controller is proposed. To grasp a physical characteristic of the inter-area oscillation frequency, the technique of overlapping decompositions is …
Genetic Diversity Of Introduced (Pomacea Canaliculata) And Native (Pila) Apple Snails In Thailand Revealed By Randomly Amplified Polymorphic Dna (Rapd) Analysis,
2017
Universiti Brunei Darussalam
Genetic Diversity Of Introduced (Pomacea Canaliculata) And Native (Pila) Apple Snails In Thailand Revealed By Randomly Amplified Polymorphic Dna (Rapd) Analysis, Thaewnon-Ngiw B., Klinbunga S., Phanwichien K., Sangduen N., Lauhachinda N., Menasveta P.
ASEAN Journal on Science and Technology for Development
Genetic diversity of the introduced golden apple snail, Pomacea canaliculata (Lamarck, 1822) and four native apple snails; Pila ampullacea (Linneaus, 1758), P. angelica (Annandale, 1920), P. pesmei (Morelet, 1889) and P. polita (Deshayes, 1830) in Thailand were studied by RAPD analysis. Two hundred and two polymorphic fragments (180-1500 bp in length) were generated across overall investigated samples (N = 254) using three informative primers (OPA07, OPB10 and UBC122). The percentages of polymorphic bands were 98.86%, 94.56%, 90.91%, 96.94% and 95.51% for Pomacea canaliculata, P. ampullacea, P. angelica, P. pesmei and P. polita, respectively. This indicated high genetic polymorphism of these …
Empirical Models For Power And Energy Requirements Ii : A Powered Implement Operation In Serdang Sandy Clay Loam, Malaysia,
2017
Universiti Brunei Darussalam
Empirical Models For Power And Energy Requirements Ii : A Powered Implement Operation In Serdang Sandy Clay Loam, Malaysia, Kheiralla A. F., Yahya A., Zohadie M., Ishak W.
ASEAN Journal on Science and Technology for Development
Power and energy requirements were measured with an instrumented tractor for rotary tilling in Serdang sandy clay loam soil. The effects of travel speed and rotor speed upon the measured data were investigated. Power model from orthogonal regression analysis was formulated based on linear and quadratic functions of travel speed and bite length. Fuel consumption model from regression analysis was formulated based on linear tractor PTO power as well as linear equivalent tractor PTO power. Fuel consumption rates predicted by ASAE D497.3 were found to be 25% to 28% overestimates of the values predicted by the model developed. However, fuel …
Efficient Reactive Power Compensation Algorithm For Distribution Network,
2017
Universiti Brunei Darussalam
Efficient Reactive Power Compensation Algorithm For Distribution Network, Jerome J.
ASEAN Journal on Science and Technology for Development
The use of automation and energy efficient equipment with electronic control would greatly improve industrial production. These new devices are more sensitive to supply voltage deviation and the characteristics of the power system that was previously ignored are now very important. Hence the benefits of distribution automation have been widely acknowledged in recent years. This paper proposes an efficient load flow solution technique extended to find optimum location for reactive power compensation and network reconfiguration for planning and day-to-day operation of distribution networks. This is required as a part of the distribution automation system (DAS) for taking various control and …
Application Of Deswirl Device In Cyclone Dust Separator,
2017
Universiti Brunei Darussalam
Application Of Deswirl Device In Cyclone Dust Separator, Abdullah M. Z., Husain Z., Fraser S. M.
ASEAN Journal on Science and Technology for Development
The experimental investigations of the vortex flow inside the vortex finder (outlet duct) of the cyclone dust separator have been carried out. Preliminary study from the visualization experiment has been performed and discovered vortex instability inside the conventional vortex finder. In order to minimize the instabilities, the streamlined entry shape was inserted at the vortex finder entrance and the results showed remarkable improvement of the vortex flow instability inside the vortex finder. The velocity measurements of two main components of velocity were performed using a laser-Doppler anemometry at the cyclone vortex finder outlet. The experiments were conducted at a constant …
Effect Of Substrate Feeding Concentration On Initial Biofilm Development In Anaerobic Hybrid Reactor,
2017
Universiti Brunei Darussalam
Effect Of Substrate Feeding Concentration On Initial Biofilm Development In Anaerobic Hybrid Reactor, Suraraksa B., Nopharatana A., Chaiprasert P., Bhumiratana S., Tanticharoen M.
ASEAN Journal on Science and Technology for Development
To elucidate the effect of substrate concentration on biofilm development, glucose concentrations of 500 and 1,000 mg/L were used. At an early stage, biofilm development at both concentrations was not significantly different (P=0.621). After removing suspended biomass at 24 operational hours, the biofilm development at high substrate concentration was higher than at lower concentration. At 72 operational hours, the amounts of attached biomass at low and high glucose feeding were 9.04±1.17 and 28.58±2.72 g VSS/m2, respectively. The activities of acidogens, acetogens, and methanogens at the low glucose concentration were 0.334, 0.016 and 0.003 g COD/g VSS/h, and those at the …
Chemical Desulphurisation Of Sub-Bituminous High Sulphur Indonesian Coal Via Peroxyacetic Acid Treatment,
2017
Universiti Brunei Darussalam
Chemical Desulphurisation Of Sub-Bituminous High Sulphur Indonesian Coal Via Peroxyacetic Acid Treatment, Ishak M.A.M., Ismail K., Nawi M.A.M., Ismail A.F.
ASEAN Journal on Science and Technology for Development
The chemical desulphurisation from an Indonesian high sulphur sub-bituminous Banjarmasin Haji Ali-Aliansar coal was investigated using the peroxyacetic acid (PAA), a mild oxidising agent. A mixture of hydrogen peroxide:acetic acid (i.e. 30:70 by volume ratio with 6% of hydrogen peroxide concentration) at 50°C of reaction temperature is capable of reducing the total sulphur content in the coal from 3.46% to 1.29% by weight, corresponding to the removal of up to ca. 72% of the total sulphur; both the inorganic (mainly pyrite) and organic sulphur forms, and approximately 10 to 44% of ashes in the coal. The simultaneous removal of both …
Removal Of Sulfur Dioxide From Flue Gas Using Absorbent Prepared By Water And Steam Hydration,
2017
Universiti Brunei Darussalam
Removal Of Sulfur Dioxide From Flue Gas Using Absorbent Prepared By Water And Steam Hydration, Teong Lee Keat, Mohamed Abdul Rahman, Bhatia Subhash
ASEAN Journal on Science and Technology for Development
Active absorbent for flue gas desulfurization was prepared from coal fly ash, calcium oxide (CaO) and calcium sulfate (CaSO4 ) by hydro-thermal process; steam and water hydration. The absorbents were examined and compared for its micro-structural properties. The experiments were conducted based on Design of Experiments (DOE) according to 24 factorial design. The effect of various absorbent preparation variables such as hydration period (Factor A), ratio of CaO to fly ash (Factor B), amount of calcium sulfate used (Factor C) and drying temperature (Factor D) towards the BET surface area of the absorbent were studied. The BET surface area of …
Application Of Back Propagation Neural Network In Predicting Palm Oil Mill Emission,
2017
Universiti Brunei Darussalam
Application Of Back Propagation Neural Network In Predicting Palm Oil Mill Emission, Azid I.A., Yusoff A.R., Seetharamu K.N., Ahmad A.L.
ASEAN Journal on Science and Technology for Development
The paper presents an approach to investigate and monitor the air pollution caused by the palm oil mill. A concept of dealing with the problem from its causes is used where the sources of pollution from the stack gases were examined. The main causes were from the combustion of shell fibre and of the palm oil. However, in the boiler itself, several parameters like steam load and pressure, fuel capacity and temperature also contribute to the pollution. The study uses Neural Network (NN) to simulate the process of combustion and stack gases. This neural network was trained by using the …
Electrochemical Behavior Of Polycrystalline Copper During The Adsorption Of Co Abstract,
2017
Universiti Brunei Darussalam
Electrochemical Behavior Of Polycrystalline Copper During The Adsorption Of Co Abstract, Salimon J., Kalaji M.
ASEAN Journal on Science and Technology for Development
The electrochemical properties of electrode copper in carbon monoxide-saturated phosphate buffered solution were investigated. The electrochemistry of copper surface was sufficiently changed after the supporting electrolyte solution was saturated with CO. The hydrogen evolution region was depressed and shifted cathodically due to the adsorption process of CO on the copper surface in a linear or terminally bonded manner, Cu-CO . The oxidation and the reduction peaks of copper were significantly changed with two couple of redox peaks. This is due to the subsequent formation and the corresponding reduction of copper(I) and the copper carbon monoxides species. Further changed in electrochemical …
Direct Synthesis Of Ladder Wave Digital Filters With Tunable Parameters,
2017
Universiti Brunei Darussalam
Direct Synthesis Of Ladder Wave Digital Filters With Tunable Parameters, Samad S.A.
ASEAN Journal on Science and Technology for Development
This paper proposes a method for the synthesis of ladder wave digital filters (WDFs) directly from the digital domain. This method avoids the need for the synthesis of analog reference filters conventionally required in WDF design. This direct method allows for the determination of the WDF coefficients from the digital domain transfer function. This is similar to conventional infinite impulse response (IIR) filter coefficient determination but the WDF will give a more efficient realization. Due to the WDFs power complementary properties, a first-order ladder WDF can simultaneously realize both lowpass and highpass responses using the same structure, while a second-order …
Immobilization Of Invertase On Carboxymethylcellulose Prepared From Nata De Coco For The Inversion Of Sucrose,
2017
Universiti Brunei Darussalam
Immobilization Of Invertase On Carboxymethylcellulose Prepared From Nata De Coco For The Inversion Of Sucrose, Fundador E.O.V., Fundador V.C. Sabularse, Revilleza M.A.J.R.
ASEAN Journal on Science and Technology for Development
Nata de coco, the cellulose produced by Acetobacter aceti with coconut water as substrate, was used as starting material in the synthesis of carboxymethylcellulose after treatment with NaOH and monochloroacetic acid. The product, referred to as carboxymethyl-“nata” (CMN), had a degree of substitution of 0.76, a higher value than those previously reported. This was used in the immobilization of invertase via ionic interaction and adsorptive forces, which produced a viscous colloidal suspension. Agar was incorporated to facilitate pellet formation. Interactions between the agar and the CMN-invertase may have resulted from ionic interactions as well as H-bonding. The immobilized enzyme retained …
Stability And Stabilization Of Nonlinear Dynamical Systems,
2017
Universiti Brunei Darussalam
Stability And Stabilization Of Nonlinear Dynamical Systems, Sattayatham P., Saelim R., Sujitjorn S.
ASEAN Journal on Science and Technology for Development
Exponential and asymptotic stability for a class of nonlinear dynamical systems with uncertainties is investigated. Based on the stability of the nominal system, a class of bounded continuous feedback controllers is constructed. By such a class of controllers, the results guarantee exponential and asymptotic stability of uncertain nonlinear dynamical system. A numerical example is also given to demonstrate the use of the main result.
Integrating Abc And Eva To Evaluate Investment Decisions,
2017
Universiti Brunei Darussalam
Integrating Abc And Eva To Evaluate Investment Decisions, Chiadamrong N.
ASEAN Journal on Science and Technology for Development
The significance of investment is transparent in the world of competitive business. Traditional costing systems in which their emphasizes are for short term savings rather than long term benefits have shown some lacking in providing accurate and reliable cost data for the investment decisions. Activity-based Costing (ABC), which is developed to satisfy some of the weaknesses of the traditional costing systems, can provide valuable insights into the operating processes and come up with more accurate cost data. In this paper, ABC is used to provide significant information for investment decisions. Although, the ABC method provides accurate operating product costs, it …
Synthesis And Characterisation Of Hydroxyl-Terminated Liquid Natural Rubber By Photo-Fenton Reaction,
2017
Universiti Brunei Darussalam
Synthesis And Characterisation Of Hydroxyl-Terminated Liquid Natural Rubber By Photo-Fenton Reaction, Pham H. L., Do B. T., Pham T. S., Le D. G.
ASEAN Journal on Science and Technology for Development
Hydroxyl-terminated liquid natural rubber (HTNR) was prepared by the photo-Fenton reaction, which was carried out in solution in the presence of H2O2/Fe(II) combined with UV irradiation. The HTNR obtained was characterized by GPC, FT-IR, 1H-NMR, 13C-NMR, DEPT-NMR spectroscopy as well as by chemical methods. A probable mechanism leading to the formation of HTNR was discussed based on the analytical data.
A Preliminary Study: Comparative Toxicity Of Extracts From Tinospora Tuberculata Beumee And Lumnitzera Racemosa Willd On Aedes Aegypti Linnaeus Larvae (Diptera: Culicidae),
2017
Universiti Brunei Darussalam
A Preliminary Study: Comparative Toxicity Of Extracts From Tinospora Tuberculata Beumee And Lumnitzera Racemosa Willd On Aedes Aegypti Linnaeus Larvae (Diptera: Culicidae), Wahizatul A. A., Shasita R.
ASEAN Journal on Science and Technology for Development
Research has been widely made on the potential use of herbal plants as effective agents for mosquito vector control. However, only a few studies have been carried out to investigate the potential insecticidal activity of mangrove plants against these dengue vectors. This study was carried out to examine the comparative toxicity of two mangrove plants, Tinospora tuberculata and Lumnitzera racemosa against the Aedes aegypti larvae. The leaf and stem of T. tuberculata and L. racemosa, were extracted using 95% methanol and these extracts bioassayed against the 3rd instar larvae of aegypti under laboratory conditions. The LC50 values of the crude …
Performance Appraisal Of Non-Governmental Organizations: A Discussion On Pakistan 2010 Floods Response And Recovery,
2017
Universiti Brunei Darussalam
Performance Appraisal Of Non-Governmental Organizations: A Discussion On Pakistan 2010 Floods Response And Recovery, Ali A., Baig N., Khan A.
ASEAN Journal on Science and Technology for Development
The paper examines in detail the role of NGOs (Non-governmental Organizations) in response and recovery phase of a disaster. Donors, INGOs (International Non-governmental Organizations) and NGOs work for the betterment of affected community but due to certain shortfalls, the community did not benefit as much as intended. In this research those gray areas are highlighted in detail through field visits and interaction with the community devastated by 2010 floods. Lack of inter-agency cooperation, partnership with inexperienced local NGOs and lack of transparency and accountability mechanisms are those areas which reduce the effectiveness of response and recovery efforts. These gray areas …
Computational Fluid Dynamics Simulations Of Gas-Liquid Two-Phase Flow Characteristics Through A Vertical To Horizontal Right Angled Elbow,
2017
Universiti Brunei Darussalam
Computational Fluid Dynamics Simulations Of Gas-Liquid Two-Phase Flow Characteristics Through A Vertical To Horizontal Right Angled Elbow, Aung N. Z., Yuwono T.
ASEAN Journal on Science and Technology for Development
Having a clear understanding on the phase distribution of gas-liquid two-phase flow through elbow bends is vital in mixing and separation system designs. This paper presents the computational fluid dynamics (CFD) simulations and experimental observations of gas-liquid two-phase flow pattern characteristic through a vertical to horizontal right angled (90°) elbow. Experimental observations were conducted in a transparent test section that consisted of a vertical pipe, elbow bend and horizontal pipe with an inside diameter of 0.036 m. The CFD simulations were performed by using a computer software package, FLUENT 6.2. Bubbly flow conditions were created in the vertical test section …
Biodegradation Of Nr Latex-Based Materials Via A Carbon Dioxide Evolution Method,
2017
Universiti Brunei Darussalam
Biodegradation Of Nr Latex-Based Materials Via A Carbon Dioxide Evolution Method, Shabinah F. M. S., Hashim M. Y. A.
ASEAN Journal on Science and Technology for Development
NR as a natural polymer has biodegradable characteristics and their existence was examined using CO2 evolution methods. The CO2 molecule produced by micro-organism metabolisms in the degradation system was quantified using a conventional acidimetric method. An aerobic system was determined as most suitable condition to be examined under this method. The presence of O2 in the system would help micro-organisms to destabilize the natural polymer. The material of LATZ, HA film and NR gloves showed significant weight loss and were able to produce CO2 evolution curves after 45 days in the biodegradation system compared to synthetic polyisoprene films. Gel permeation …
Effects Of Chocolates Using Low Calorie Cocoa Butter Substitutes On Rat’S Plasma Profile And Determination Of Sn-1,3 Position,
2017
Universiti Brunei Darussalam
Effects Of Chocolates Using Low Calorie Cocoa Butter Substitutes On Rat’S Plasma Profile And Determination Of Sn-1,3 Position, Ros-Haniza B.., Mamot S.
ASEAN Journal on Science and Technology for Development
The present study sought to determine the effectiveness of newly developed low calorie chocolate using modified fat through enzymatic interesterification process as cocoa butter substitute of male Sprague Dawley rats (n = 35) compared to cocoa butter as control. Body weight gains did not differ significantly (p>0.05) in all the test groups fed with chocolates which were using different types of fats. Triacylglycerol and cholesterol test showed no significant difference (p>0.05) for all treatment samples. in this study, a pancreatic lipase hydrolysis was performed to determine the fatty acid composition of the sn-2 position of the structure lipids.
