Response of suction distribution due to variations of permeability in residual soil slope

A landslide in residual soil normally occurs immediately after heavy rainfall. Previous studies have shown that decrease in matric suction during rainfall decreases the shear strength of soil and results in landslides. One of the factors that contribute to infiltration of water into soil is permeability of the soil which varies with depth. The variations of permeability can either prevent or allow water to infiltrate into deeper soil layer. Therefore, the aim of this study is to determine the suction distribution in a two-layered residual soil system with variable permeability function using laboratory physical slope model. The Ksat for Grade V varies from 5.11 × 10-4 m/s for relict joint of 100 mm spacing to 5.40 × 10-5 m/s for relict joint of 300 mm spacing. Meanwhile the Ksat for Grade VI represent Grade VI without burrow holes, 5.00 × 10-7 m/s and Ksat with burrow holes, 6.98 × 10-4 m/s. The infiltration tests were conducted for 12 series of experimental program. The suction distribution due to variations of permeability and rainfall intensity were determined. The results illustrated that suction distribution responded in various ways depending on permeability of the layered soil and also the rainfall intensity

Machinability Evaluation of Nanoparticle Enriched in Vegetable-Based-Nanofluids for Machining Process

Vegetable oil had been study to replace mineral based oil as metalworking fluids (MWFs) as it is non toxic, bio-degradable and environmental friendly. Due to vegetable oil’s high viscosity and poor thermal conductivity, some improvement had been applied to vegetable oil such as chemically modified and the addition of additives. The aim of this study to evaluate the machining performance of modified jatropha oil (MJO) with nanoparticle additives of 0.025wt% copper oxide(Cuo) (MJOc) and 0.025wt% hexagonal boron nitride(hBN) (MJOh) as metalworking fluids. The machining performance of MJOc and MJOh were compared with the commercial synthetic ester (SE) through turning process in terms of cutting temperature, surface roughness, tool life and tool wear. The result show that the machining performance of MJOc and MJOh were better compared to SE. In terms of cutting temperature and surface roughness, MJOh shows better maching performance compared to MJOc. In addition, MJOh had same tool life performance with SE which is at cutting length of 6000mm and machining time of 42 minutes. In conclusion, the overall best machining performance is MJOh (MJO+0.025wt% hBN) and has a potential as sustainable MWFs in lubricant market

Improvement of cylinder buckling knockdown factor through imperfection sensitivity

This paper encompasses the work from numerical model by investigating the compression response of CFRP composite cylinder shells. The aim of this paper is to improve the reliability of NASA SP-8007 design guideline. The cylinder geometrical imperfections were tested through numerical modelling and validate with the experiment results. Good results comparison has been obtained through the work with small amount of errors. The cylinder shell load carrying capacity has been improved by average of 56% through imperfection study. This work builds confidence in the future use of non-linear finite element for the design of composite cylinder subjected to axial compression load

INVESTIGATING THE NATIONAL DIGITAL CADASTRAL DATABASE (NDCDB) DATA HANDLING WITHIN GIS APPLICATIONS

This paper explains the investigation carried out to understand NDCDB data handling within GIS applications. The method used was a case study replicated to five established GIS applications from different agencies, namely eKadasOnline, SKiP, iPlan, TM SmartMap and DBKL Interactive Portal. The case study was propositioned to the statements of; i) “Such methods of applying NDCDB are because user understands its characteristics”, and ii) “such methods of applying NDCDB are because users know how to adopt it.” Cross-case comparison analysis was then conducted to identify rival findings and explanation building. Based on the evidence of the multi-case study, it was concluded that such methods of adopting NDCDB by the GIS applications administrators and developers were because most of them have a partial understanding of the NDCDB characteristics which led to NDCDB being adopted based on the method that they think were suitable. Recommendations are highlighted in this paper to rectify knowledge-based mistakes found in this study, that included; i) ensuring the NDCDB’s cut-off-date; ii) utilises all existing NDCDB layers; iii) ensure to use the map projection parameters are the authorised and official value; iv) understand that the NDCDB utilises the GDM2000 datum with ITRF2000 epoch 2006; v) False Easting and North Easting can be discarded for geocentric datum; vi) adopting the built-in Geocentric Cassini map projection of GIS software is not advisable; and vii) obtaining relevant additional NDCDB layers. With the recommendations emplace, it is hoped the full potential of NDCDB can be tapped especially for multipurpose cadastre implementation including to ease spatial analysis. Data replication, exhaustion of resources, and reduce risks or costly investments made by decision makers, policy makers, developers or individuals can be avoided when NDCDB is fully optimised for spatial analysis

Dam Break Analysis of Batu Dam using Hec-Ras

Dam is commonly built in Malaysia as it provides benefits to the local population, mainly agricultural activity and flood control measures. However, its massive potential energy reservoir would impose risk of sudden containment breach leading to loss of life and property at inhabited downstream area. Simulations of dam break events are crucial to characterizing and reducing threats due to potential dam failures. In all post-event natural disasters, where most structural countermeasures have been lost, the preparation of a smoother evacuation mechanism remains the most critical prevention tool for successful evacuation planning. The urgency of designing an appropriate emergency planning is important in response to the disaster. To perform a dam break analysis, hydraulic modeling is required, which involves routing the inflow flood through a reservoir, estimating dam breach characteristics, and downstream routing/modeling issues. The HEC-RAS (River Analysis System) software is commonly used for dam break studies. The software provides information on how to perform a dam break analysis, including the unique hydraulic modeling aspects that are required. Batu dam has the highest percentage of the population at risk (PAR) and most likely exposed to the flood disaster due to dam break. From flood boundary maps, it was estimated that 78% of residential areas would be affected if a dam break disaster occurs. From the simulation, the maximum depth can reach up to 18m with an estimated flow speed between 0.2 – 3m/s. At these depth and flow speed, people may lose strength and unable to control themselves in flood and would cause death and injury. Flood arrival time took 15 to 22 hours for flooding to arrive downstream with a maximum flood depth of 5.07m at Persiaran Jasa Utama and the highest depth of 12.62m at Kampung Baru Batu Caves with flood velocity between 1.60m/s to 1.46m/s. Analysis and simulation of embankment dam breach events and the resulting floods are crucial for distinguishing and mitigating dangers from potential dam failures. Accurate forecast of inundation levels and the time of flood wave arrival at downstream key places is required for the development of effective emergency response plans

Laboratory investigation of suction distribution in a modified capillary barrier system

This paper investigated the effect of transport layer in the diversion capacity of natural capillary barrier system using laboratory slope model. The slope model was constructed with stainless steel and 5 mm thick acrylic sheets. Grade VI and grade V soils classified as sandy silt of very high plasticity (MVS) and silty gravel of high plasticity (MHG), respectively were arranged in the slope model with sand and gravel transport layers sandwiched at their interface. The model was subjected to different rainfall intensities using rainfall simulator to determine the behaviour of water flow and suction distribution in the slope model. The results obtained show a modification in the suction distribution behaviour and the natural capillary barrier effect was sustained. It was also observed that a transport layer formed with gravel material was more effective in diverting the infiltrating water compared to that of gravelly sand. This occurred because the upper grade VI layer possessed capillary forces due to its finer pore structures and relatively large air entry value, thus, it retained the infiltrating water, and the gravel transport layer possessed relatively larger pore structures compared to the grade VI layer and hence it possessed higher hydraulic conductivity values and small water entry value. This arrangement, provide a capillary break and allowed the infiltrating water to flow above the interface. Therefore, the inclusion of transport layer provides a definite path through which the infiltrating water flows and diverted laterally. Thus, improving the performance of natural capillary barrier effect

Docking study for assessment of wound healing potential of isosakuratenin isolated from Chromolaena odorata: An In-silico approach

Wound healing is a complex and well-orchestrated biological process in all multicellular organisms in which normal wound healing consists of four major phases that are haemostasis, inflammation, proliferations and reepithelization. Abnormal wound healing is always associated with inefficient or miscarried transition during inflammation to proliferation phase. Wound healing potential of various natural extracts have been studied progressively in recent years. In this present study, isosakuratenin, a phytoconstituent previously reported to be isolated from the extracts of Chromolaena odorata are aimed at targeting essential proteins involved in wound healing process. Matrix Metalloproteinases (MMP) is a protein essential in wound healing. Therefore, the present study is aimed to evaluate the inhibitory effect of isosakuratenin on MMP as a potential therapeutic target for wound therapy. Isosakuratenin from Chromolaena odorata were studied based on their ability to interact with the targeted protein via molecular docking approach. Isosakuratenin showed binding affinity to four different classes of MMPs. The binding energy of these MMPs with isosakuratenin are -7.7 kcal/mol (MMP2), -6.8 kcal/mol (MMP3), -9.0 kcal/mol (MMP8) and -9.7 kcal/mol (MMP12). Isosakuratenin forms stronger interaction with MMP12 in which it forms two bonding at the active site of the protein and shows the most stable dock conformation. This results suggested that, among these four MMPs, isosakuratenin are best interacted with MMP12 and hence, could be used to visualized the potential of isosakuratenin as MMP12 inhibitor during wound healing process. This recent work provides meaningful insights in regards to the molecular structure interaction and requirement of the phytoconstituents from Chromolaena odorata for subsequent pharmaceutical formulation in catering the wound healing products demand

Optical Nonlinear Properties of Gold Nanoparticles Synthesized by Laser Ablation in Polymer Solution

In the present study, gold nanoparticles were synthesized in various polymer solutions by means of employing laser ablation technique at the same ablation time. Specifically, gold nanoparticles were synthesized in polyethylene glycol and chitosan solutions, in order to compare the effects of the liquid media which served as stabilizers for particle size and volume fraction of nanoparticles. In addition, this experiment was repeated in distilled water for reference purposes. As the findings indicated, the particle size which was obtained in polyethylene glycol was about 7.49 nm, that is, smaller than those of chitosan solution and distilled water, respectively. In contrast, it was observed that the volume fraction of gold nanoparticles increased in polyethylene glycol in comparison with the other media which indicated an effect on the formation of NPs. On the other hand, Z-scan technique was employed to measure the nonlinear refractive index and nonlinear absorption coefficient of nanofluids containing gold nanoparticles. Consequently, the nonlinear properties of nanofluids pointed to a significant contribution with the number of nanoparticles observed in fluids and both optical nonlinear parameters were observed to increase by means of a prior increase in the volume fraction of Au-NPs in polyethylene glycol solution

Friction and wear phenomena of vegetable oil based lubricants with additives at severe sliding wear conditions

The tribological responses of palm oil and soybean oil, combined with two commercial antiwear additives (zinc dialkyl dithiophosphate and boron compound), were investigated at a lubricant temperature of 100 °C and under severe contact conditions in a reciprocating sliding contact. The friction coefficient of palm oil with zinc dialkyl dithiophosphate was closest to the commercial mineral engine oil, with a 2% difference. The soybean oil with zinc dialkyl dithiophosphate produced a 57% improvement in wear resistance compared to its pure oil state. The existence of boron nitride in vegetable oils was only responsive in reduction of wear rather than friction. The response of commercial antiwear additives with vegetable oils showed a potential for the future improvement in the performance of vegetable oils