Advanced Materials Research Vol. 974

Abstract: Durability means the resistance to physical or chemical deterioration of concrete resulting from interaction with environment (physical deterioration) or interaction between constituents (chemical deterioration) of concrete. A durable concrete ensures corrosion resistance of embedded steel which in turn ensures a better longevity of the structure as a whole. Concrete in structures in the coastal areas are the most susceptible to chemical deterioration as sea water, with high concentration of chloride ions, has quite a detrimental effect on durability of concrete. In these cases, the lower the chloride permeability, the better the durability of concrete. As instruments for standard chloride permeability test is very expensive, an experiment has been conducted to carry out Rapid Chloride Permeability Test (RCPT) using improvised apparatus made of readily available low-cost materials. Several RCPT tests were performed using this simple method and results showed marked variation in chloride permeability for concrete with different quality.

Abstract: The results of considering the path effect and without considering the path effect computed by MIDAS/Civil are different, while the path effect can reflect the real stress of system in construction, but the deformation can not meet the construction standard. So we eliminate the stress of system and deformation accumulation in construction by changing the process of construction and using the hydraulic jack.

Abstract: Larger displacement and inter-force response of the structure will be produced when self-anchored cable-stayed suspension bridge in longitudinal earthquake. Engineering practice proved that the viscous damper has obviously damping effect for structure. For the vibration reduction system of self-anchored cable-stayed suspension bridge, whose main tower is set viscous damper. This essay does the nonlinear time history analysis under the longitudinal earthquake about the vibration reduction system that considering the LRB putted in different location. Compared with the damping system that only set viscous damper, analysis results show that inter-force and displacement of control section and control node are reduced greatly in hybrid vibration control.

Abstract: At the East of Thailand, a shortage of river sand for producing concrete has frequently occurred while the large amounts of quarry dusts are being produced as by-products of stone crushers in many stone quarries. Then, the quarry waste from 12 stone quarries (in Rayong and Chonburi province) was taken to investigate the engineering properties as fine aggregate for concrete. The properties - namely type of parent rock, specific gravity, water absorption, gradation, fineness modulus (F.M.), organic impurities level, powder content, plastic index and sand equivalent value - were examined. The results show that the parent rocks of the samples are limestone, granite and rhyolite. The specific gravity of samples were in the range of 2.61 - 2.77. The gap gradations are found in all samples and the F.M. values slightly exceed the limit of ASTM standard. Absorption of quarry dust is high (around 2 %). Although the high powder contents are found in all samples, the powder in quarry waste is non-plastic and non-organic material. Therefore, gradation and absorption of quarry waste could be carefully considered or improved before using quarry waste as fine aggregate in concrete.

Abstract: This paper discusses parameter estimations of step response from biodiesel transesterification process. The estimates signal generated from impedance measurement from sunflower oil transesterification process. 15 kHz AC signal has used to characterize the capacitance value during the process. The recorded signal then processed using Matlab system identification toolbox. The parametric identification method is selected to develop model structure. The model structure has modelled based on three different structures, ARMAX, BJ and ARX. The algorithm generated from identification toolbox as well as validation test. The validation test including correlation and cross correlation test. ARMAX structure appeared to be best between the others structure.

Abstract: Precise control of fuel injection is essential in modern diesel engines especially in controlling the precise injection quantity, flexible injection timing, flexible rate of injection with multiple injections and high injection pressures. It was known that the fuel-air mixing is mainly influenced by the fuel injection system and injector nozzle characteristics. Thus, mixture formation during ignition process associated with the exhaust emissions. The purpose of this study is to investigate the influence of spray characteristics on the mixture formation. In this study, common rail injector systems with different model of injector were used to simulate the actual mixture formation inside the engine chamber. The optical visualization system was constructed with a digital video camera in order to investigate the detailed behavior of mixture formation. This method can capture spray penetration length, spray angle, spray evaporation and mixture formation process clearly. The spray characteristic such as the penetration length, spray angle and spray area are increasing when the injection pressure increased. The mixture formation can be improved effectively by increasing the injection pressure.

Abstract: Gas lift is an artificial lift method which is commonly used in offshore operation with sufficient gas sources as it consumes minimum space on the platform. Gas lift operates by injecting a high pressure gas down through the tubing casing annulus of a well and the injected gas enters the tubing through a gas lift valve installed on the tubing. Gas lift increases production by two means, density reduction of oil column inside the tubing so that the flowing bottom-hole pressure which is affected by the hydrostatic pressure of the fluid column is reduced and by providing external energy to the oil as the gas expends.Reducing the bottom-hole pressure will improve the drawdown of the well. A production well is modelled by using a production modelling program, Integrated Production Modeling (IPM) Prosper to analyze the production performance at various conditions. A base case model is developed from the production data of an actual oil field to simulate the performance of the actual well without gas lift system. Later, the gas lift is added to the model and the performance was compared with the base case model. The gas parameter was also studied to determine the optimum injection gas condition for maximum oil production. The gas injected at 1490m can be achieved by injecting the gas with 1200 psi, l300 psi or 1400 psi. However, the optimum gas injection pressure was determined to be at 1400 psi as the design shows that the required unloading stage is the least. The optimum gas injection rate was determined at 5 MMscf/d with the estimated net revenue is the highest. For injection gas gravity, the lighter gas was determined to be the optimum selection since it gives significant reduction of FBHP (Flowing Bottom Hole Pressure) with less hydrostatic pressure inside the tubing column.

Abstract: Many methods to reconstruct the corneal topography are based on the Placido disk system. The skew rays can contribute errors to the system when using the reflection image with these methods. To overcome this limitation, a backward ray tracing technique is developed. By performing this technique, a continuous surface representation of the cornea is obtained. The error analysis shows an enhanced accuracy in reconstructing the corneal topography. The colormaps of corneal surface powers are also drawn for graphic representations of corneal topography.

Abstract: The rapidly expanding cottage textile sector – which is due to increasing demand - has greatly contributed to Malaysia’s economic growth. Unfortunately, this growing industry is also creating a lot of environmental issues associated with textile effluents and it has become a public concern. Innovative solution such as biological technology is preferable as it can reduce the destructive impact on the ecological system. The goal of this research is to study the effectiveness of Lactobacillus delbrueckii and Pleurotus ostreatus at decolorizing remazol dyes that exist in textile effluents. Both microbes had exhibited good color removal of between 50 - 70 % in less than 120 hours with optimum conditions for decolorization occuring at pH 7.0, dye concentration of 0.2 mL/mL, and temperature at 37°C.

Abstract: Proper waste management in Malaysia is needed for the organic wastes such as pineapple leaf and cassava peel where affects the increase the amount of solid waste dump into landfill. Thus, to overcome this problem agro waste material can be constructed in many production industries to commercialize the use of alternative fibre for the paper industry. The main objective of this study is to demonstrate the use of fibrous in pineapple leaf and cassava peel by production of alternative fibre based on chemical properties and surface morphology characteristic. This study conducted for the chemical composition by analysed by TAPPI Test method, Chlorination method and Kuchner-Hoffner method. Every chemical components analyse; Cellulose (Kuchner-Hoofner), Holocellulose (Chlorination method), Hemicellulose (Chlorination method), Hemicellulose, Ash content (T211-om-93), Lignin content (T222-om-98) and Sodium Hydroxide soluble (T203-om-88). The scanning electron microscopy (SEM) was used to observe and determine the morphological characteristic of both crops. The result indicates that pineapple leaf more suitable for becoming an alternative fibre than cassava peels. Pineapple leaves have a high Holocellulose content (85.7%), cassava peels 66%, followed by Cellulose pineapple leaf (66.2%), cassava peels (37.9%). However, hemicellulose content in pineapple leaf (19.5%) less than cassava peels (37.0%). Lignin content of pineapple leaf is lower (4.2%) compared to cassava peels (7.52%) in this study. From SEM images, cassava peel contained abundance fibre such as hemicellulose and cellulose that is held by the lignin in it and Pineapple leaves give a condensed composition of fibre structure. The chemical compositions and morphology study of pineapple leaf and cassava indicate pineapple leaf have a high percentage to be used as an alternative pulp in paper making industry, promoting the green technology. However, cassava peels make some of properties that can also be through for the paper industry.