bluuebunny/crossref_metadata_2025 huggingface dataset:
Volatile Fatty Acids Production through Degradation of Biomass by Anaerobic Digestion (Mesophilic and Thermophilic)
Authors: Rahim Ahmad Fitri Abd , Kutty Shamsul Rahman Mohamed , Ezechi Ezerie Henry
Published: June 2014

Volatile fatty acids (VFAs) are fatty acids with a carbon chain of six carbons or fewer and usually referred to as short-chain fatty acids (SCFA). Degradation of biomass through anaerobic digestion will produce volatile fatty acid (VFAs) through anaerobic digestion process. The volatile fatty acids obtained can be recovered and used to produce methyl or ethyl esters which, could be advantageously used as additive for biodiesel [1]. Anaerobic digestion is a biological process that can degrade waste organic material by concerted action of a wide range of microorganisms in the absence of oxygen. The objective of this study is to degrade the biomass through anaerobic digestion for the production of volatile fatty acids by two different temperatures condition which are mesophilic and thermophilic; 35°C and 55°C respectively. The production of volatile fatty acids was optimized by varying the cycle period of the digestion process with the concentration of Mixed Liquor Suspended Solid (MLSS) maintained at 8000 mg/L for each cycle. The degradation of biomass was carried out using anaerobic sludge digester which 2L of biomass was digested from day 1 until day 24 (cycle period). The tests of MLSS and Mixed Liquor Volatile Suspended Solid (MLVSS) was conducted by Standard Method 2540-D while test for VFAs was conducted through Standard Method 8196. The highest production of volatile fatty acids was obtained in day 5 of cycle period where the concentration is 441 mg/L as acetic acid (HOAC).
Development of Platform Selection Tool for Offshore Decommissioning in Malaysia
Authors: Zawawi Noor Amila Wan Abdullah , Lun Na Kai , Liew M.S.
Published: June 2014

Decommissioning of offshore structures is not a novel issue in the oil and gas industry. Malaysia is now dealing with a fleet of ageing platforms slated to be decommissioned. There are several alternatives of decommissioning such as “complete removal” and conversion to artificial reefs; “partial removal”, “remote reefing” and “topple in-situ”. Given the list of options, the decision to undertake the best option is challenging as the current method of comparative Best Practicable Environmental Option (BPEO) assessment is only implemented at the end of platform’s life. Therefore, the main goal is to develop a management decision making tool which is incorporated throughout the life cycle of an oil field. Expert elicitation is conducted to verify the relevant decommissioning criteria. The criteria were then ranked accordingly through calculation of Relative Importance Index (RII), and a conceptual system is established to complement the existing asset management system. In summary, this study could benefit the knowledge of offshore decommissioning planning through prioritization of decommissioning criteria.
Dynamic Response of Free-Span Sub-Sea Pipelines under Vortex Induced Vibrations
Authors: Charanvarma S. , Shashikala A.P.
Published: June 2014

Study of dynamic behavior of pipeline is required to access fatigue life of pipeline welds. Semi-empirical mathematical model is thus proposed to calculate responses of free-span pipelines under vortex induced vibrations. A two equation model interacted through velocity coupling with a non-linear stiffness term for pipeline model and a non-linear damping term for wake is considered. The proposed model is found to represent the real situation of responses to a greater extent.
Effects of Marine Growth on Hydrodynamic Coefficients of Rigid Tubular Cylinders
Authors: Al-Yacouby A. M. , Kurian V. John , Sebastian A.A. , Liew M.S. , Idichandy V.G.
Published: June 2014

In this paper the wave induced hydrodynamic forces and the corresponding hydrodynamic coefficients for a 42 mm diameter model pipe subjected to regular waves was investigated experimentally and the results were compared with the responses of a similar rigid cylinder fitted with marine growth. The main objective of this study was to quantify the effects of marine growth on the hydrodynamic forces experimentally and determine the associated hydrodynamic coefficients. The experimental data were generated from a set of wave tank model tests and the results were scaled up using a scale factor of 1:55. The thickness of marine growth applied on the model pipe was varied with respect to the water depth in the ratio of 3:2:1. Regular waves were generated with wave heights ranging from 0.02 m to 0. 2 m for modal period varying from 0.6 s to 3.25 s. The tests were conducted for Keulegan-Carpenter number ranging from 3.9 to 23.3. The findings of the experimental results revealed that increasing the thickness of the full scale prototype cylinder by 110 mm due to marine growth fittings, has increased the overall wave hydrodynamic forces by 16 to 90% depending on the wave heights and the wave frequencies at which the model was tested, proving that the drag coefficients have considerably increased.
Finite Element Assessment of Difficult Pipelines at Bends
Authors: Mustaffa Zahiraniza , Albarody Thar M. Badri , Roshdi Azrulfirdaus Muhamad
Published: June 2014

This paper presents numerical assessment of difficult pipelines at bends using the finite element method (FEM). Difficult pipelines are those that are unable to be inspected using a pig inspection tool. These unpiggable pipes, especially at the bend sections, exhibit difficulties to be piggable for several reasons, thus they are exposed to hazards that can neither be inspected nor controlled. The structural response of the bends is then required to be investigated. This paper aims at simulating the structural response of bends caused by internal corrosions using the ANSYS FEM software. Circular pitting corrosion at different depths and diameters were applied to simulate the stress distribution for three pipe models, namely standard 90° pipe bend, miter bend and unbarred full-bore tees pipe bend near dead end. The results of different corrosion equivalent stress distribution were compared and the most reliable type of bend was reported.
Effect of Low Pressure on Irrigation Uniformity of Solid Set Sprinkler Irrigation System
Authors: Osman Manal , Hassan Suhaimi B. , Yusof Khamaruzaman Wan
Published: June 2014

The irrigation requires an efficient and effective method of water application to realize maximum return and conserve water resources. The low pressure sprinkler irrigation system is the most commonly used due to: its low energy cost, but the irrigation uniformity of this system is not constantly good because it is affecting by the design factors such as: nozzle type, nozzle diameter, operating pressure and spacing layout. But the most important factors are the operating pressure and nozzle diameter. In this study the effect of low pressure on the irrigation uniformity of the solid set sprinkler irrigation system was studied. Different low operating pressures (62, 82, 102 and122 kPa) were selected and different nozzle diameters (4, 5 and 7 mm) were used. The solid set layout was square (12 m between the sprinklers along the line and 12 m among the line). The catch-cans test was used to determine the uniformity coefficients such as: Christiansen’s coefficient of uniformity (CU), coefficient of variation (CV), distribution uniformity of low quarter (DUlq) and distribution uniformity of low half (DUlh). The distribution characteristics such as: throw radius and rotation speed were monitored. A comparison was made between the results obtained from different combination of operating pressures and nozzle diameters. The results of this study showed that, CU, DUlq and DUlh were increased when the pressure increased for all the nozzles. The greater values of CU, DUlq and DUlh were found with the combination of 7 mm nozzle diameter and 122 kPa. The coefficient of variation was increased when the pressure decreased for all the nozzles. The throw radius and rotation speed were increased gradually when the pressure increased. The throw radius was not significantly affected by the nozzle diameter while the rotation speed was more affected by the nozzle diameter.
System Reliability of Existing Jacket Platform in Malaysian Water (Failure Path and System Reliability Index)
Authors: Kurian V. John , Abdul Wahab Mohamed Mubarak , Kheang T.S. , Liew Mohd Shahir
Published: June 2014

The objective of this work is to determine the structural reliability of an existing jacket platform in Malaysia, by determining the system probability of failure and its corresponding reliability index. These two parameters are important indicators for assessing the integrity and reliability of the platform, and will point out whether the platform is suitable for continued operation. In this study, pushover analysis is used to determine possible failure paths of the structure, while First Order Reliability Method (FORM) and Simple Bound Formula are used to determine the failure probability and reliability index. Three failure paths of the platform are established. The reliability index of these paths is found with the highest Reliability Indexto be 18.82 from the 315-degree path, while the system reliability index is 9.23. This illustrates that the platform is robust and the chances of collapse is very small.
Wave Transmission over a Submerged Porous Breakwater an Experimental Study
Authors: Teh Hee Min
Published: June 2014

The present paper presents an experimental study of wave transmission for a trapezoidal submerged porous breakwater located in the nearshore region. Wave transmission characteristics of the breakwater subjected to unidirectional monochromatic waves have been ascertained via a systematic test program. A series of tests have been conducted to study the effect of porosity of the breakwater on wave transmission, and to assess wave attenuation performance of the breakwater in relation to wave steepness and the relative breakwater width. The test results have indicated that the breakwater of 20% porosity offers the highest hydraulic efficiency, and the breakwater provides higher wave suppression ability when exposed to shorter period waves particularly in shallow waters.
A Novel Method for Monitoring Hydration Process of Cement Paste Material
Authors: Al-Mattarneh Hashem , Alwadie Abdullah , Malkawi Ahmad , Nuruddin Muhd Fadhil
Published: June 2014

A new measurement system is developed to monitor the early hydration of cementitious materials based on measured dielectric properties of the material in low electromagnetic frequency range. The objectives of this paper were to evaluate the changes in the electromagnetic properties for samples with different fly ash content and to establish the reliability of the measurement technique by comparing with results obtained by traditional method such as thermal method that is either time consuming or impractical. The method adopted in the present experimental work is a parallel plate electrode system (PPES). The suggested monitoring device for concrete hydration and strength development is based on the relationship between the electromagnetic properties such as dielectric constant, loss factor and the strength development during hydration process and curing time. In this research the electromagnetic properties of concrete is found to be dependent on the hydration and strength of concrete. Therefore the development of microstructure and concrete compressive strength can be determined by monitoring its electromagnetic properties in the frequency range of 1 to 100 kHz.
Drying Shrinkage of Fly Ash-Based Self-Compacting Geopolymer Concrete
Authors: Nuruddin M.F. , Memon F.A. , Shafiq N. , Demie S.
Published: June 2014

–The drying shrinkage behaviour of fly-ash-based self-compacting geopolymer concrete (SCGC) was studied for a period of one year. Two SCGC and One OPC-based conventional mixture were used in the present investigation. Drying shrinkage test commenced on the 7th day after casting the test specimens. Once the appropriate curing regime was completed, the specimens from each mix were placed in the laboratory room where the temperature was maintained at 23°C, however, the relative humidity of the room varied between 56 and 64 percent. Strain readings taken at specific intervals were analyzed to determine the time-dependent deformations of each mixture. Test results indicated that the heat-cured fly ash-based SCGC experienced very low drying shrinkage than that of water-cured OPC based concrete. After one year of exposure, in comparison to 466 με, the value experienced by OPC concrete, the drying shrinkage strains of SCGC mix specimens ranged between 141 and 159 με. These values were about 65-70% lower than that of OPC concrete. It is anticipated that the findings of this investigation would help in predicting the behaviour of SCGC.
Keywords-Fly ash, Geopolymer concrete, Self-compacting Geopolymer concrete, Drying shrinkage
Effects of Groundwater Withdrawal on the Interaction of Ex-Mining Pond, River, and Aquifer
Authors: May Raksmey , Yusoff Ismail , Tahir Wardah
Published: June 2014

The paper aims at evaluating the effects of groundwater abstraction on the interaction of an ex-mining pond, river, and aquifer system of the Langat Basin in Malaysia through a 3D numerical modeling. Many mining sites have been left behind from the massive mining exploitation in Malaysia. In the current study, an artificial recharge from an ex-mining pond in the Langat Basin was proposed due to its capacity to store >30 million m3 of water. The 3D numerical model was developed using the Visual MODFLOW to simulate the effects of these activities. The calibrated model was utilized to simulate two cases. The ex-mining pond was without and with pumping in Case 1 and 2, respectively. Both results showed that the pond and aquifer were in influent condition. In Case 1, the total inflow to the aquifer system were approximately 15,819 m3/d of water from the constant heads, 1,202 m3/d from the Langat River, and 66,951 m3/d from the direct recharge of precipitation. In Case 2, due to the abstraction of groundwater, it caused a steep depression around the pumping well, river, and pond. The result of the water budget showed an increase rate of the inflow to the pumping zone from the pond and river around 6,945 m3/d compared to Case 1. The outcome of the current study provides the useful information of the interactions between the river, pond, and aquifer system as regards the groundwater abstraction in the Langat Basin.
Effect of MIRHA and Fly Ash in Ductile Self-Compacting Concrete on Abrasion and Impact Performance
Authors: Nuruddin Muhd Fadhil , Azmee Norzaireen Mohd , Chang Kok Yung
Published: June 2014

The benefits of Microwave Incinerated Rice Husk Ash (MIRHA) as partial cement replacement materials in DSCC mixes has led to the research on the possibilities of combining both MIRHA and fly ash as an addition in DSCC replacing up to 20% of cement volume whilst maintaining satisfactory properties. The addition of both materials can improve concrete properties and reduce the cost of DSCC production. These supplementary cementitious materials are expected to give positive effects on the concrete abrasion and impact resistance. The incorporations of both MIRHA and fly ash in DSCC as cement replacement materials are considered as a new type of concrete. Therefore, it is important to have a complete knowledge on the behaviour of the composite material when being subjected to repetitive dynamic loading. The test results showed that MIRHA and fly ash combination in DSCC improved both abrasion and impact resistance of DSCC compared to reference specimens.
Effective Method of Repairing RC Beam Using Externally Bonded Steel Plate
Authors: Alam Md Ashraful , Jabbar Ali Sami Abdul , Jumaat Mohd Zamin , Mustapha Kamal Nasharuddin
Published: June 2014

Repair of reinforced concrete beam with externally bonded steel plate or fibre reinforced polymer (FRP) laminate is becoming both environmentally and economically preferable rather than replacement of deficient beam. The well known advantages of external reinforcement over other methods include; low cost, ease of maintenance and the ability to strengthen part of the structure while it is still in use. The disadvantage of this method, however, is the premature debonding of the externally bonded strips which is brittle and undesired mode of failure. It is also known that debonding of the externally bonded steel plates prevents the reinforced concrete (RC) beam from reaching its full strengthening capacity. The aim of this study was to increase the scientific understanding on the behaviour of damaged reinforced concrete beams strengthened and/or retrofitted for shear using vertical steel plate fixed with adhesive and steel connectors to eliminate or delay debonding failure. Four reinforced concrete beam specimens were prepared to investigate the effects of connectors in preventing or delaying premature debonding of shear strips to restore the capacities of fully damaged beams. Three damaged beams have been repaired and strengthened with steel plates and loaded monotonically up to the maximum load capacities in order to define load–deflection relationship. It is concluded that the repairing of severely shear-damaged RC beams with steel plates by using steel and adhesive connectors can fully restore the original shear capacities of the beams.
Flexural Behaviour of Concrete Beams Bonded with Wire Mesh-Epoxy Composite
Authors: Qeshta Ismail M.I. , Shafigh Payam , Jumaat Mohd Zamin , Abdulla Aziz Ibrahim , Alengaram Ubagaram Johnson , Ibrahim Zainah
Published: June 2014

This paper investigates the flexural performance of plain concrete beams bonded with wire mesh-epoxy composite. A total of four beam specimens were prepared and tested. Three specimens were bonded with same amount of wire mesh-epoxy composite with varying composite width and one plain concrete specimen was used as a control. The effect of wire mesh-epoxy composite on enhancing the flexural behaviour of concrete beams as well as the effect of different configurations of composite was studied. Test results showedthat the wire mesh-epoxy composite increased the flexural strength of concrete beams. The increase in energy absorption of bonded beams was remarkable. In addition, specimen with large composite width showed better behaviour with respect to energy absorption capability.
Single-Degree-of-Freedom Based Pressure-Impulse Diagrams for Blast Damage Assessment
Authors: Syed Zubair Imam , Liew Mohd Shahir , Hasan Muhammad Hasibul , Venkatesan Srikanth
Published: June 2014

Pressure-impulse (P-I) diagrams, which relates damage with both impulse and pressure, are widely used in the design and damage assessment of structural elements under blast loading. Among many methods of deriving P-I diagrams, single degree of freedom (SDOF) models are widely used to develop P-I diagrams for damage assessment of structural members exposed to blast loading. The popularity of the SDOF method in structural response calculation in its simplicity and cost-effective approach that requires limited input data and less computational effort. The SDOF model gives reasonably good results if the response mode shape is representative of the real behaviour. Pressure-impulse diagrams based on SDOF models are derived based on idealised structural resistance functions and the effect of few of the parameters related to structural response and blast loading are ignored. Effects of idealisation of resistance function, inclusion of damping and load rise time on P-I diagrams constructed from SDOF models have been investigated in this study. In idealisation of load, the negative phase of the blast pressure pulse is ignored in SDOF analysis. The effect of this simplification has also been explored. Matrix Laboratory (MATLAB) codes were developed for response calculation of the SDOF system and for repeated analyses of the SDOF models to construct the P-I diagrams. Resistance functions were found to have significant effect on the P-I diagrams were observed. Inclusion of negative phase was found to have notable impact of the shape of P-I diagrams in the dynamic zone.
Strengthening Schemes for Flexure and Torsion Using FRP Laminates: A State of Art Review
Authors: Imran Muhammad , Shafiq Nasir , Akbar Ibrisam
Published: June 2014

RC beams as a structural member contain a variety of non-uniform loads. These non-uniform loads caused combined effects of flexure and torsion. There are numerous studies available, that suggests different strengthening schemes using FRP laminates, as a solution for flexure and torsion deficient beams. Most of the experimental studies suggested individual strengthening schemes for flexure or torsional deficiency RC beams. However, the combined effects were not studied due to difference in experimental setup, testing procedure and specimen detailing. Therefore, the outcome of previous studies was needed to combine together to facilitate the strengthening process as a guideline case of such deficiency. Therefore, a combined review is presented by suggesting different configuration for flexure and torsion deficient RC beams. Most of the studies suggested that the application of FRP laminates at the soffit of beam is suitable for flexural strengthening. The application of U-shape or full wrap are suitable for strengthen torsion deficient beams. Similarly, 45° wraps are more effective than 90°wraps for improving ductility of torsion deficient beams.
The Effect of Palm Oil Fuel Ash as a Cementreplacement Material on Self-Compacting Concrete
Authors: Alsubari Belal , Shafigh Payam , Jumaat Mohd Zamin , Alengaram Ubagaram Johnson
Published: June 2014

In this study ground palm oil fuel ash (POFA) has been used as cement replacement in percentages of 0%, 10%, and 20% in a self-compacting concrete (SCC). Fresh properties such as slump flow, T50, V-funnel, J-ring, L-box and segregation index; concrete properties such as drying shrinkage strain, initial surface absorption test (ISAT) as well as compressive strength were investigated. Test results showed that substitution of cement with POFA up to 20%, the fresh properties of the concrete fulfilled the requirements of a self-compacting concrete. The results revealed that concrete has higher compressive strength, lower drying shrinkage, and lower initial surface absorption than control mix. The results indicated that POFA can be used up to 20% as a cement replacement material for producing self-compacting concrete.
Challenges for Implementation of Building Information Modeling (BIM) in Malaysian Construction Industry
Authors: Gardezi Syed Shujaa Safdar , Shafiq Nasir , Nuruddin Muhd Fadhil , Farhan Syed Ahmad , Umar Usman Aminu
Published: June 2014

The construction industry of Malaysia is very dynamic in nature and the adoption of new technological advancements and construction methods has been a prime concerns for its key players and stakeholders. However, the adoption of BIM in such a dynamic industry is observed to be limited and its implementation has not been as successful as it should have been. The study focuses on the identification and prioritization the factors challenging the implementation of BIM in Malaysian construction industry. The data has been administrated through designed questionnaire by identifying the factors / barriers, by literature review, for implementation of BIM in construction industry. The prioritization of such factors is expected to help the major stake holders to address the issues according to their priority which will save lot of previous time and financial with smooth implementation of BIM in Architecture, Engineering and Construction (AEC) industry in future project.
Major Challenges to the Sustainable Operations of Construction Equipment in Malaysia
Authors: Waris Muhammad , Liew Mohd Shahir , Khamidi Mohd Faris , Arazi I.
Published: June 2014

The growing considerations of people, profit and planet have emphasized the integration of sustainable concepts in the construction processes. The previous research in sustainable construction has underlined the issues pertaining to raw material and its manufacturing; design aspects along with the occupancy phase of a building life cycle. However, concerned over GHG emissions from the operation of non-road diesel equipment are still being ignored in the established literature. These non-road construction equipment consume fossil fuel and a serious threat for green environment. In addition to this, health and safety issues are also important concerns for the human well-being. Thus, mitigating these impacts are the important aspects of sustainable planning for onsite construction activities. A questionnaire survey was carried out to explore the contractors views towards potential challenges that are relevant with the growing attention of sustainability in construction sector. A group of large civil contractors of Malaysian construction industry were solicited through online survey to prioritize the potential barriers. The research findings presents a broader view and a number of challenges that inhibits the contractors for acquiring, adopting and implementing sustainable practices for onsite mechanized construction activities.
Number of Bidders in Small and Medium Public Construction Procurement in Malaysia
Authors: Azman Mohd Azrai
Published: June 2014

A competitive bidding price depends on a number of bidders who enter the auction. It increases the intensity of competition and it reduces the purchasing cost. The number of bidders is important because the cost of bidding may become a sunk cost. The probability to win an auction depends on the expected number of bidders. This affects bidders' decisions on whether to bid or not to bid. The research uses several statistical analyses to examine the 195 bidding data collected from Public Works Department of Malaysia. It finds that the project value, the distance from the project site to supply source and state region affect the number of bidders.
The Performance Measurement of Supply Chain Management (SCM) in Malaysian Infrastructure Project
Authors: Wahab Mohamad Razali Abd , Ahmad Hayroman
Published: June 2014

The infrastructure project is a great challenge to the key player due it volume and complexity. The problem facing by most of infrastructure project in term of management aspect, such as management conflict and unsatisfied output becomes an obstacle to fulfill the government strategy mainly Malaysia. Supply Chain Management (SCM) is viewed as a strategic tool to tackle that issue but there is a lack of comprehensive view of SCM concept and lack of reliable measure which contribute to improper guideline to the practice of SCM. Due to that this paper aims to identify reliable performance measure of SCM through perception of key player in infrastructure project. The indicator for performance measure of SCM is based on survey that carried out on 116 key players of Malaysian Infrastructure Project. Statistical techniques were used to form, verify and test the reliability of the questionnaire. The conceptual classification of the previous literature review and justification of experts during the pilot study proposed six (6) indicators for measuring performance of supply chain management (SCM). However, in this study five (5) indicators have been identified, namely Information Dissemination, Management, Leadership, Relationship Development, Customer Management and Activities Sequences. Hence this measure could be used to evaluating and control the performance of supply chain and as a guidance for a new initiatives to improve and develop supply chain.
Assessing UAV Landslide Mapping Using Unmanned Aerial Vehicle (UAV) for Landslide Mapping Activity
Authors: Mokhtar Munirah Radin Mohd , Matori Abdul Nasir , Yusof Khamaruzaman Wan , Embong Abdul Mutalib , Jamaludin Muhammad Ikhwan
Published: June 2014

The purpose of this research is to improve the landslide mapping using unmanned aerial vehicle (UAV) for the area of slope displacement. It further presents the UAV namely multi-motor that being used to capture images at the research area located in Parit, Perak. The objective of this research paper is to develop a three dimensional of landslide area produced from the UAV images. For the whole process of image processing, thirty six control points are established using global positioning system (GPS) staic mehtod using Agisoft Photoscan. The results show that the digital elevation model (DEM), aspect Model, slope model, and digital orthophoto can be obtained using the procedure and method used in the study. The information is obtained through accurate assessment results and used to create a 3D model which is then used to monitor technique applications. The restitution stereo model is also by three dimensional rotations or transformation in 3D surface. From here, the landslide can be detected by calculation of three difference epoch data achieved from Digital Elevation Model (DEM) generation. Prior to that, this paper focuses on the monitoring of that area based on DEM area and volume generated from 3D surface analysis. To conclude this study shows that UAV can be used for producing digital map.
Bearing Capacity of Shallow Foundation's Prediction through Hybrid Artificial Neural Networks
Authors: Marto Aminaton , Hajihassani Mohsen , Momeni Ehsan
Published: June 2014

The utilization of Artificial Neural Network (ANN) for bearing capacity estimation has some disadvantages such as getting trapped in local minima and slow rate of learning. Recent developments of optimization algorithms such as Particle Swarm Optimization (PSO) have made it possible to overcome ANN drawbacks and improve its efficiency. This paper presents a unified approach of ANN based on PSO algorithm to predict bearing capacity of shallow foundations in granular soils. To generate the network, numbers of 40 datasets including the recorded cases of full-scale axial compression load test on shallow foundations in granular soils were collected from literatures. Each dataset refers to a set of 6 inputs consisted of footing length and width, embedded depth of the footing, average vertical effective stress of the soil, friction angle of the soil, and ground water level as well as one output consisted of the ultimate axial bearing capacity. Several sensitivity analyses were conducted to determine the optimum parameters of PSO algorithm and the network architecture was determined following the trial and error method. The results demonstrate that the presented model predicts the bearing capacity of shallow foundations with high degree of accuracy.
Comparison of Seismic Performance between Single and Double Unit Tunnel Form Building under In-Plane Lateral Cyclic Loading
Authors: Anuar Shamilah Anudai , Hamid Nor Hayati Abdul
Published: June 2014

This paper summarizes the comparison of seismic performance between single and double unit tunnel form building (TFB) under in-plane lateral cyclic loading. Experimental work was carried out to determine the lateral strength capacity, stiffness, ductility, and equivalent viscous damping (EVD) for both specimens. The comparisons of these parameters for both specimens were made to determine its percentage difference. The maximum lateral strength capacity obtained from single unit TFB with 8.68% higher than double unit TFB. As for stiffness behaviour, single unit was found to be much more stiffened compared to double unit. The EVD value showed that single unit absorbed much more energy compared to double unit of TFB. However, double unit TFB indicated a significant percentage of increment compared to the single unit TFB. Therefore, double unit TFB is safer to be built compared to single unit especially for seismic regions.
Measuring Driver’s Percent-Time-Spent-Following Using a Moving Video Recording Technique
Authors: Muttaka Na’iya Ibrahim , Bin Chepuan Othman
Published: June 2014

The percent time spent following (PTSF) or proportion of following time (PFT) relative to total travel time taken by vehicles to traverse a particular segment of two-lane highways has been used as key performance index for evaluating the level-of-service of the road. From the context of travel time, this implies that PTSF is a space related indicator and thus supposed to be measured over a road segment. However, this indicator is measured in the field based on specific point observation; as equivalent to the percent of vehicles traveling with time headways shorter than 3 s. The accuracy of PTSF estimates based on this approach has been questioned and criticized by many; as spot measured values may not to be real representative of segment estimates. This paper presents an exploration into the application of moving video recording technique for PTSF measurement. PTSF was estimated based on test vehicle following time on two-lane highways using moving car observer method as an alternative approach for field measurement of the indicator along road segment as opposed the existing practice of spot measurement and assumed representative of long segment. Findings from this work demonstrate that the approach used in this study is promising for field measurement of PTSF; as estimates obtained relate well with the major vehicle’s following cause factors.
Investigation of Modified Mangrove Bark on the Sorption of Oil in Water
Authors: Robabeh Asadpour , Sapari Nasiman , Isa Mohamed Hasnain , Orji Kalu Uka
Published: June 2014

Today oil spills generally cause worldwide worry due to their damaging effects on environment. Use of agricultural wastes such as raw and modified mangrove barks (RhizophoraApiculata), as an abundant and low cost adsorbent for oil-products spill cleanup in aquatic systems, has been developed to control these spills. Sorption capacity can improve by modification of adsorbent. The modification significantly increased the hydrophobicity of the adsorbent. The raw mangrove bark was modified using fatty acid (Palmitic acid) to improve its adsorption capacity. Oil sorption capacity of the modified bark was studied and compared with the raw bark. Kinetic tests were conducted with a series of contact time. The kinetic studies show good correlation coefficients for a pseudo-first-order kinetic model. A correlation between surface functional groups of the adsorbent was studied by FTIR spectrum. The results gave the maximum adsorption capacity of 2640.00 ± 2.00 mg/g for Palmitic acid treated bark (PTB). The prepared adsorbent revealed the potential to use as a low-cost adsorbent in oil-spill clean-up.
Statistical Analysis of Dynamic Bearing Capacity of Driven Pile
Authors: Arsyad Ardy , Suyadi Suyadi , Samang Lawalenna
Published: June 2014

This paper presents the use of statistical-probabilistic method in determining pile bearing capacities over a number of driven piles. Four dynamic formulas were employed to estimate pile bearing capacity including modified ENR, Hiley, Navy – McKay and Danish. We investigated the final setting data of 47 concrete piles with 600 mm diameter in the construction projects of New Naval Engineering Building Hasanuddin University. Based on the data, pile bearing capacity were computed and then analyzed statistically. Goodness of fit with Kolmogorov-Smirnov and Shapiro-Wilk were used to fit the probability distribution function (PDF) of the pile bearing capacity data to the PDF model. It was found that the pile bearing capacity estimated using ENR is more uniform with 506 tons average pile capacity and 6.4% COV, while that with Hiley and Danish are less various with 252 tons and 346 tons average pile capacity, and 14.7% and 16.6% COV respectively. Navy-McKay was found to have 465.8 tons average pile capacity with higher variability of 44.08%. A 90% Probability of pile bearing capacity estimated by ENR is 535 tons, or 1.17 times the upper bound, and 1.4 times the lower bound of pile capacity measured by pile driving analyzer (PDA). In comparison, 90% probability estimated by Danish is 420 tons or 0.93 times and 0.92 of the upper and lower bound of pile capacity measured by PDA, respectively. The Navy-McKay seeems to be overestimated whereas Hiley is underestimated.
Application of Geographic Information System (GIS) and Analytic Network Process (ANP) for Sustainable Tourism Planning in Cameron Highlands, Malaysia
Authors: Aminu Mansir , Matori Abdul Nasir , Yusof Khamaruzaman Wan , Zainol Rosilawati Binti
Published: June 2014

This paper discusses an approach based on an integrated use of GIS and ANP for sustainable tourism planning of Cameron Highlands, Malaysia. ANP was utilized to evaluate the relative priorities for the sustainable tourism development of the highland based on chosen criteria and indicators (elements). Pair wise comparison technique was used in order to evaluate possible alternatives from different perspectives. Having derived the weights from the pairwise comparison method, unweighted supermatrix, weighted supermatrix and the limit supermatrix were then computed. The limit supermatrix was normalized to derive the priorities; the result was then transferred into GIS framework. Elements evaluated and ranked are represented by criterion maps. The criterion maps were evaluated by reclassifying the data layers, to represent different needs for the sustainable tourism development of the highland. Spatial models reflecting the views of experts involved were aggregated using the weighted sum method of GIS. Subsequently sustainable tourism development model was generated, which will ensure that future generations benefit from the natural endowments of Cameron Highlands.
Langat River Basin Hydrologic Model Using Integrated GIS and ArcSWAT Interface
Authors: Ali Mohd Fozi , Rahman Nor Faiza Abd , Khalid Khairi , Liem Nguyen Duy
Published: June 2014

Increase of socio-economic activities in the urban area has led to many water scarcity problems. Thus, the need to investigate the current state of Langat river is increasing. An integrative computational model, ArcSWAT with GIS interface was being used to predict daily stream flow of the study area. Historical data from years 1999 to 2010 was used for modeling purposes. The results reviewed that the calibrated model is able to simulate the flow for the river basin successfully with the R2 = 0.64 and Nash-Sutcliffe Index, NSI= 0.64. The results proved that GIS technology and ArcSWAT model is capable for simulating the stream flow in the Langat river basin and can be applied for other river basins. This shows that SWAT can be a tool for a hydrologic modeling in Malaysia in the future.
Optimization of Activated Sludge Physical Properties by Magnetic Field via Response Surface Modeling
Authors: Nur Syamimi Zaidi , Muda Khalida , Sohaili Johan , Sillanpää Mika
Published: June 2014

In this study, activated sludge was exposed by magnetic field exhibited from NdFeB – type of permanent magnets. The exposure was aimed to improve the physical properties of the activated sludge used in treating wastewater. Hence, it was hypothesized that the magnetically-exposed activated sludge is potential in enhancing the efficiency of removal performances of the wastewater treatment processes. The influence of magnetic field, exposure time, biomass concentration and mixing intensity on turbidity reduction, aggregation and settling velocity was thoroughly investigated. Response surface methodology (RSM) was applied for experimental design, analysis and optimization. Based on the results, magnetically-exposed activated sludge displayed certain trends showing that its properties were positively affected by magnetic field. At the optimum conditions of magnetic field of 88.0 mT, exposure time of 38.5 hrs, biomass concentration of 3380 mg/L and mixing intensity of 345 rpm achieved 68.3%, 60.1% and 0.0104 cm/s of turbidity reduction, aggregation and settling velocity, respectively.
Electrical Conductivity Properties of Nd2O3 Doped LiCl-PbO-ZnO Glass Ceramics
Authors: Sathish M. , Eraiah B.
Published: June 2014

xNd2O3-35LiCl-(30-x)PbO-35ZnO glasses (where x=0.1, 0.2, 0.3, 0.4 and 0.5 mol %) were prepared by melt quenching method and converted to glass ceramics by controlled crystallization processes. Glass and glass ceramic phases were confirmed by XRD. The electrical conductivity of these samples has been carried out as a function of frequencies at different temperature. Ac conductivity data of these glasses has been analyzed using a single power law. The exponents obtained from the power law fits is found to be in the range from 0.2 0.3 in these glass ceramics and shows moderate temperature dependence. The stretched exponent β also is seen to vary slightly with temperature. Scaling behavior also has been carried out using the reduced plots of conductivity and frequency. The time-temperature superposition of data points is found to be satisfactory indicating that the ion transport mechanism decreases with annealing temperature and increase with compositions studied. Activation energy (Ea) has been calculated for all the samples at different temperatures, is found to vary in the range of 0.4eV to 0.5eV.
Investigation of Optical Properties of ZnO/MnO2, ZnO/TiO2 and ZnO/MnO2/TiO2 Nanocomposites
Authors: Shanmuganathan G. , Shameem Banu I.B.
Published: June 2014

ZnO nanocomposites such as (ZnO)0.8(MnO2)0.2, (ZnO)0.8(TiO2)0.2and (ZnO)0.8(MnO2)0.1(TiO2)0.1were prepared by solid state reaction method at room temperature. The structural analysis was carried out with help of powder XRD to confirm the formation of the composites. The morphological properties and presence of elemental compositions were analyzed with scanning electron microscope and energy dispersive analysis spectroscopy respectively. Optical properties were studied with UV visible spectrophotometer. From the transmittance spectrum, it is concluded that the synthesized composite materials have the transmittance in the range of 80 to 95% in the visible region. The calculated optical band gap values for pure ZnO is 3.16 eV and the values are 3.7eV, 5.27eV and 4.46eV for the composites ZnO/MnO2, ZnO/TiO2and ZnO/MnO2/TiO2, respectively. The study has found that the ZnO/MnO2, ZnO/TiO2and ZnO/MnO2/TiO2composites have very large energy gap as that of insulator.
Studies on the Depolymerization of Poly(ethylene terephthalate) Using 1, 1, 2, 2-Tetramethyl-1-Benzyl-2-n-Octyl Ethylene-1, 2-Diammonium Bromide Chloride as Phase Transfer Catalyst
Authors: Narayanan V. Lakshmi , Umapathy M.J.
Published: June 2014

1,4-Bis (dimethyl) benzyl octyl ethylene diammonium bromide chloride has been synthesized, characterized and applied as new phase transfer catalyst in the alkaline hydrolysis of PET leading to depolymerisation. The new phase transfer catalyst has been compared with the alkaline hydrolysis of PET using zinc sulfate as catalyst in the depolymerization. It was found that the newly synthesized phase transfer catalyst exhibited excellent conversion than the alkaline hydrolysis of PET using zinc sulfate as catalyst.
Cadmium Selenide Quantum Dots - MWCNTs Nanocomposite Modified Electrode for the Determination of Epinephrine
Authors: Kalaivani Arumugam , Narayanan Sangilimuthu Sriman
Published: June 2014

A novel Cadmium selenide Quantum dots MWCNTs nanocomposite modified electrode was achieved by simple drop casting method and its application towards the quantitative determination of epinephrine. The Cadmium selenide Quantum Dots was characterized by transmission electron microscopy and MWCNT was characterized by scanning electron microscopy. The electrochemical characteristics of the modified electrode were studied using cyclic voltammetry. The voltammetric response of the modified electrode was higher than that of the MWCNT and bare electrodes. The modified electrode exhibits excellent electrocatalytic activity towards the oxidation of epinephrine by enhancing its oxidation current in 0.1M phosphate buffer solution. The determination range of epinephrine is from 0.16 μM to 14 μM and the detection limit was 0.05 μM (S/N = 3). The proposed modified electrode exhibited good stability and reproducibility.
Effect of Stirring on Hydrophobicity of PVDF/CNT Nanocomposite Coatings
Authors: Prasad G. , Anand Prabu Arun
Published: June 2014

Multi-walled carbon nanotubes (MWCNTs)-Polyvinylidene fluoride (PVDF) superhydrophobic coatings were prepared by a facile phase separation and spray coating method. The effect of phase separation and stirring on wettability has been studied. A transformation of hydrophobic to super-hydrophobic state is achieved with increasing CNT content. In the absence of CNTs, the neat PVDF coatings exhibited water contact angle (WCA) of 105o. A gradual increase in WCA is observed with increasing addition of CNTs, and reaches to super-hydrophobic state (WCA > 150o) for CNT content of 33%. FTIR studies revealed a stronger interaction between PVDF and CNT with increasing stirring time. FESEM images and EDAX data show uniform morphology and higher fluorine content, respectively for samples stirred for longer time when compared to shorter stirring time, and the results are discussed in detail.
Nanocomposites Based on High-Tc Superconducting Ceramic 2212 BSCCO and their Properties
Authors: Jayasree T.K. , Predeep P.
Published: June 2014

High temperature superconducting (SC) 2212 BiSrCaCuO nanoparticles were prepared by Sol-Gel method. Precursor was characterized by X-ray diffraction (XRD) and scanning Electron micrography. The superconductor nanocomposites were fabricated by nanoparticles of the SC powder with NR/LLDPE blends. The superconductive properties of the sintered samples and the nanocomposites were studied. Transition to a superconducting state around 88K appeared in the parent sample and in the composites. The scanning electron microscopic investigation of the nanostructures of SC polymer ceramic nanocomposites shown nanoscale dispersion of BSCCO in the polymer phase uniformly.
Synthesis and Characterization of Bi2S3 Nanorods Decorated on Carbon Sphere and Study its Electrochemical Application
Authors: Devendran P. , Alagesan T. , Pandian K.
Published: June 2014

Bismuth sulfide(Bi2S3) nanorods(NRs) decorated on uniform shape carbon sphere(CS)have been prepared by hydrothermal method, using single source precursorpolyvinyl pyrrolidone(PVP) as a capping agent. The nanoparticles were synthesized with different ratio of capping agent at different temperatures.The prepared nanoparticles were characterized by FTIR spectroscopy,thermo gravimetric and differential thermal analysis. The crystallinity, morphology and elemental composition of the synthesized nanocrystals have been confirmed through X-ray diffraction (XRD), HRSEMand EDX. The electrochemical catalytic activity on the reduction of catechol of the synthesized Bi2S3NRs has been investigated.The electrocatalytic oxidation of catechol done with Bi2S3NRs coated CS/GCE modified by using CV and the effect of the scan rate also studied. The modified nanocomposites Bi2S3NRs on CS in GCE are act as a good sensor by detection of catechol in ultra trace level by using DPV techniques.