193 research outputs found

    Kejuruteraan asas

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    A phylogenetic study of endo-beta-1,4-glucanase in higher termites

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    Cellulose is the most abundant polymer in the world and termites are the most important metazoan cellulose processors. Termites are divided into lower and higher termites, with the latter being the most derived and most specious. Although termites are known for their ability to digest wood, members of the family Termitidae (higher termites) are nutritionally diverse in their use of cellulose. This study investigated the evolution of endogenous cellulases in 25 species of higher termites, using phylogenetic inferences from mitochondrial (16S) and nuclear (28S) ribosomal RNA and endo-β-1,4-glucanase sequences. The translated endo-β-1,4-glucanase amino acid order in all 41 sequences obtained showed high similarity to endo-β-1,4-glucanases in the glycosyl hydrolase family 9. The inferred endo-β-1,4-glucanase phylogenetic tree showed congruency with the mitochondrial/nuclear tree, with the fungus-growers being the most basal group and the soil/litter- and wood/lichen/grass/litter-feeders being the most distal diphyletic feeding groups. The bacterial comb-grower formed a separate clade from the fungus-growers and is sister groups with the soil/litter- and wood/lichen/grass/litter-feeders. There was also a strong diphyletic relationship between endo-β-1,4-glucanases of upper layer soil-feeders and the other soil-feeders. Within the monophyletic wood/lichen/grass/litter-feeding termites’ subclade, the nasutitermitines were polyphyletic and a strong diphyletic relationship was observed in the most distal lichen- and the grass/litter-feeders groups

    Observational Methods for Predicting Embankment Settlement

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    The one dimensional Terzaghi method is still widely used for prediction of settlement. Its differential equation is solved on the assumption that coefficient of consolidation is a constant, in which case the equation becomes linear. But in reality this equation is non linear because compressibility, permeability and coefficient of consolidation changes with settlement. This is why the capability of predicting the rate of settlement or time-settlement relationship remains rather poor. In this paper a number of high quality long-term field settlement data are used to verify the applicability of the observational methods, namely the hyperbolic and the Asaoka method. The field data were from the Tangkak trial embankment (1987-1996) and the Juru trial embankment (1990-1992). Based on the available settlement record for embankment on soft ground, it can be concluded that the prediction of settlement using the hyperbolic method is significantly improved using the start of construction settlement data, notably after more than 50% of the settlements have occurred. Long-term settlement predicting using the early stage data (6 months or less) could be misleading. The capability of the method can also be diagnosed from the characteristics of the CUIVe plotted. For the case of hyperbolic method, it is evident that if a close linear relation of t/p and p is obtained, then the prediction is seemingly good. Prediction of settlement using the Asaoka method is also improved using larger settlement database

    Effect of acid rain on geotechnical properties of residual soils

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    In this study, the effect of acid rain on the physico-chemical and microstructural properties of two different residual soils was investigated. In order to reproduce the process of soil-acid rain-chemical interaction, an infiltration setup was fabricated. The samples were then infiltrated by different pH levels of acid rain, and for different fluxes of acid rain equivalent to the precipitation, for 1–20 years. The compressive strength, consistency limit, compaction characteristics, and coefficient of permeability were evaluated, to investigate the mechanical changes of the soils after being exposed to acid rain. In addition, zeta potential, atomic adsorption spectroscopy (AAS), scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDX) were carried out to identify the underlying controlling mechanisms. The results showed that low pH and high fluxes of acid rain led to a reduction in soil strength and maximum dry density as well as an increase in the coefficient of permeability, liquid limit, and optimum moisture content of the soil. The SEM, EDX, and atomic absorption analysis of the soils confirmed the reduction in the concentration of elements, and the loose structure for both soils due to the effects of acid rain

    Effect of Mixing Fine Sand on the Drained Shear Strength of Completely Decomposed Granite Soil.

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    Experimental test results presented in this paper were from a series of triaxial compression tests studied under drained conditions for Completely Decomposed Granite (CDG) soil mixed with fine sand content of (0, 10, 20, 30, and 40%). The CDG soil showed high compressibility during isotropic consolidation, probably due to the use of the moist tamping method and the effect of weathering degree on the soil structure. The tests results produced a unique Critical State Line (CSL) in the e-lnp plane, and these lines were parallel for each mixture and moved downward with increasing fine sand content. The fine sand content, at which the intergranular void ratio of the CDG-fine sand mixture became equal to emax for plain CDG soil, was named as Transition Fine Sand Content (TFSC), which occurred at 20-30% fine sand content. Normalization of the critical state stresses showed that for the samples with low P/Pc between 0.58 and 0.65 (i.e. the CDG soil mixed with fine sand), the stress paths moved directly towards the critical state without passing through the boundary surface of the soil mixture, which revealed the impact of the fine sand addition to the CDG soil structure, reflecting an improvement in the soil strength behavior by developing a strong interlocking among the particles of the mixture. It was also observed that a small portion of stress paths could pass through the boundary of Hvorslev surface in the case of low fine sand content (≤ 10 %) and the boundary of Hvorslev surface observed clearly in the case of plain CDG soil. The friction angle increased at steady state from 28- 32.6, and the cohesion decreased from 15 to 8.3 kN/m2 with increasing fine sand content. A comparison of critical state parameters and strength properties between weathered granite CDG soil from Malaysia and Hong Kong were also made and summarized in this study

    Evaluating The Effects of Signal Control Applications on Roundabout’s LOS Performance Using VISSIM Microsimulation Model

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    The existence of unbalanced and high traffic flows at roundabout have resulted in poor performance and safety concerns. Past research has shown that applications of signal control at problematic roundabouts had significantly improved its Level of Service (LOS) performance. This study investigates the effects of different signal phasing plans on the roundabout’s LOS performance using VISSIM microsimulation model. The findings revealed that both Approach-Signal-Control Roundabout ACSR and Two-Stop-Line Control Signalized Roundabout TSLSR signal phasing methods did not significantly improve the roundabout’s entry capacities. Partial signal control applications, however, have resulted in a significant reduction in vehicle delays and higher entry capacities. The results of this study provide a good overview to local traffic practitioners on how to evaluate and implement the signal control strategy at problematic roundabouts. &nbsp

    Dynamic Creep Performance of Hot Mix Asphalt Mixture Incorporating Fibre

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    Permanent deformation is one of the distress that develops gradually as the number of load applications increases and appears as longitudinal depressions in the wheel paths and small upheavals to the sides. For this reason, numerous studies conducted on modification asphalt binder or mixture by various fibre. This paper presents the evaluation of creep modulus and permanent deformation of modified asphalt mixture with fibres. In order to envisage the modified asphalt mixture, Forta-fi, Kenaf and PET was blended to estimate the creep properties and rut depth value at different loading pattern. Superpave mix design method was employed with NMAS 12.5mm to obtain the optimum bitumen content established at 4% air void. In the respect, bitumen 60/70 penetration grade with 0.5% of Forta-Fi, 0.1% Kenaf fibre and 0.5% PET by weight of asphalt mixture were prepared. Dynamic Creep Test was performed in accordance to the EN 12697-25:2005 guidelines using the Universal Testing Machine (UTM). As the result, the minimum value of permanent deformation was found at 0.5% of PET. Based on these studies, adding a minimum percent of PET in the asphalt mixture shows a better resistance to rutting deformation and enable a better understanding of the properties in modified asphalt mixtures

    Evaluating The Effects of Signal Control Applications on Roundabout’s LOS Performance Using VISSIM Microsimulation Model

    Get PDF
    The existence of unbalanced and high traffic flows at roundabout have resulted in poor performance and safety concerns. Past research has shown that applications of signal control at problematic roundabouts had significantly improved its Level of Service (LOS) performance. This study investigates the effects of different signal phasing plans on the roundabout’s LOS performance using VISSIM microsimulation model. The findings revealed that both Approach-Signal-Control Roundabout ACSR and Two-Stop-Line Control Signalized Roundabout TSLSR signal phasing methods did not significantly improve the roundabout’s entry capacities. Partial signal control applications, however, have resulted in a significant reduction in vehicle delays and higher entry capacities. The results of this study provide a good overview to local traffic practitioners on how to evaluate and implement the signal control strategy at problematic roundabouts. &nbsp

    THE TRANSFORMATION OF TRADITIONAL FOLKLORE INTO ANIMATION: IMPACT ON TODAY’S SOCIETY

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    Abstract As most of the local folklores are not properly documented, the move to transform local folklore into animation is indeed a good news. However, whether the transformation of the folklore into animation maintains its originality in terms of certain important elements, remain unknown. This matter can become an issue in the future, especially among the community in which the folklore belongs to. Therefore, the objective of this study is to analyze the original and the animated versions, in terms of theme, plot, main cast, setting, and values, particularly among the local folklores in the state of Sarawak (East of Malaysia). This study uses qualitative descriptive method in order to examine the folklores. Three animated folklores from Sarawak namely ‘Apai Saloi Hunting’, ‘The Legend of Santubong’ and ‘Commander of Mount Sadok’ were used as prime sources of the study. Data were also collected from people’s statement, written documents, historical heritage, and information from the internet. The results of the study revealed that all the three folklores have at least 95% of similarity between the original version and the animated version. The present study also provides information about the impact and contribution of animated folklore toward the society. It is hoped that more local folklores will be transformed into animated version by maintaining its originality, so that the intangible cultural heritage is being preserved and protected. Keywords: Folklore, Transformation, Animation, Impac

    Dynamic Creep Performance of Hot Mix Asphalt Mixture Incorporating Fibre

    Get PDF
    Permanent deformation is one of the distress that develops gradually as the number of load applications increases and appears as longitudinal depressions in the wheel paths and small upheavals to the sides. For this reason, numerous studies conducted on modification asphalt binder or mixture by various fibre. This paper presents the evaluation of creep modulus and permanent deformation of modified asphalt mixture with fibres. In order to envisage the modified asphalt mixture, Forta-fi, Kenaf and PET was blended to estimate the creep properties and rut depth value at different loading pattern. Superpave mix design method was employed with NMAS 12.5mm to obtain the optimum bitumen content established at 4% air void. In the respect, bitumen 60/70 penetration grade with 0.5% of Forta-Fi, 0.1% Kenaf fibre and 0.5% PET by weight of asphalt mixture were prepared. Dynamic Creep Test was performed in accordance to the EN 12697-25:2005 guidelines using the Universal Testing Machine (UTM). As the result, the minimum value of permanent deformation was found at 0.5% of PET. Based on these studies, adding a minimum percent of PET in the asphalt mixture shows a better resistance to rutting deformation and enable a better understanding of the properties in modified asphalt mixtures
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