615 research outputs found

    Simulation of sub-drains performance using visual MODFLOW for slope water seepage Problem

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    Numerical simulation technique was used for investigating water seepage problem at the Botanic Park Kuala Lumpur. A proposed sub-drains installation in problematic site location was simulated using Modular Three-Dimensional Finite Difference Groundwater Flow (MODFLOW) software. The results of simulation heads during transient condition showed that heads in between 43 m (water seepage occurred at level 2) until 45 m (water seepage occurred at level 4) which heads measurement are referred to mean sea level. However, elevations measurements for level 2 showed the values between 41 to 42 m from mean sea level and elevations for level 4 between 42 to 45 m from mean sea level. These results indicated an increase in heads for level 2 and level 4 between 1 to 2 m when compared to elevations slope at the level 2 and level 4. The head increases surpass the elevation level of the slope area that causing water seepage at level 2 and level 4. In order to overcome this problems, the heads level need to be decrease to 1 until 2 m by using two options of sub-drain dimension size. Sub-drain with the dimension of 0.0750 m (diameter), 0.10 m (length) and using 4.90 m spacing was the best method to use as it was able to decrease the heads to the required levels of 1 to 2 m

    Simulation of sub-drains performance using visual MODFLOW for slope water seepage Problem

    Get PDF
    Numerical simulation technique was used for investigating water seepage problem at the Botanic Park Kuala Lumpur. A proposed sub-drains installation in problematic site location was simulated using Modular Three-Dimensional Finite Difference Groundwater Flow (MODFLOW) software. The results of simulation heads during transient condition showed that heads in between 43 m (water seepage occurred at level 2) until 45 m (water seepage occurred at level 4) which heads measurement are referred to mean sea level. However, elevations measurements for level 2 showed the values between 41 to 42 m from mean sea level and elevations for level 4 between 42 to 45 m from mean sea level. These results indicated an increase in heads for level 2 and level 4 between 1 to 2 m when compared to elevations slope at the level 2 and level 4. The head increases surpass the elevation level of the slope area that causing water seepage at level 2 and level 4. In order to overcome this problems, the heads level need to be decrease to 1 until 2 m by using two options of sub-drain dimension size. Sub-drain with the dimension of 0.0750 m (diameter), 0.10 m (length) and using 4.90 m spacing was the best method to use as it was able to decrease the heads to the required levels of 1 to 2 m

    Error correction and uncertainty measurement of short-open-load calibration standards on a new concept of software defined instrumentation for microwave network analysis

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    Software-Defined Radio (SDR) has appeared as a sufficient framework for the development and testing of the measurement systems such as a signal generator, signal analyzer, and network analysis used in the network analyzer. However, most of researchers or scientists still rely on commercial analyzers were larger benchtop instruments, highly cost investment and minimum software intervention. In this paper, a new concepts measurement revolution called as Software Defined Instrumentation (SDI) on network analysis is presented, which is based on reconfigurable SDR, a low-cost implementation, ability to access RF chain and utilizing open source signal processing framework. As a result, a Vector Network Analyzer (VNA) has been successful implemented by deploying an SDR platform, test sets, and data acquisition from the GNU Radio software in host PC. The known calibration process on SHORT-OPEN-LOAD (SOL) technique is validated to ensure measurement data from this SDI free from systematic error. Two types of SOL calibration standards used for a comparison study to validate the SDI measurement system which is capable of generating the response on the differential of standard quality and accuracy of standards kits. Finally, calibration uncertainty analysis is also presented in this work by utilizing RF open source package without any cost addition

    An overview of moisture damage performance tests on asphalt mixtures

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    This paper presents a review of moisture damage performance tests on asphalt mixtures. The moisture damage remains to be a detriment to the durability of the Hot Mix Asphalt (HMA) pavement. Moisture damage can be defined in forms of adhesive failure between bitumen and aggregates and cohesive failure within bitumen. Aggregate mineralogy, bitumen characteristics and anti-stripping additive dominantly influence the performance of asphalt mixtures towards moisture damage alongside construction methods, climate and traffic loading. Various laboratory test methods have been developed to quantify the moisture damage performance of asphalt mixtures by resembles the action in the field, including qualitative test such as Boiling Water Test (ASTM D3625) and quantitative tests such as Modified Lottman Test (AASHTO T283). Both of these tests consist of two phases, which are conditioning and evaluation phase. This paper will review the effectiveness of the selected available tests based on various asphalt mixtures materials. Generally, this study indicates that asphalt mixtures consisted of limestone aggregates, modified bitumen and addition of anti-stripping additives will provide more resistant towards moisture damage

    EXTRACTION AND MICROENCAPSULATION OF POLYPHENOLS FROM ORTHOSIPHON STAMINEUS LEAVES

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    This paper presents an extraction and microencapsulation study of polyphenols obtained from Orthosiphon stamineus leaves. Extraction using aqueous solvent enabled a simultaneous extraction of both hydrophilic and lipophilic phenolic compounds. Higher solid concentration leads to higher solution viscosity, bigger particle size, lower moisture content and a less dented surface, which may improve particle flowability. The results suggest that eupatorin and rosmarinic acid are more susceptible to thermal degradation than sinensetin during spray drying. The formulation of 1:9 whey protein to maltodextrin ratio was also found to be more effective, with 86.7% total flavonoids retention compared to other formulations, viz, 1:1 and 9:1. This paper presents an extraction and microencapsulation study of polyphenols obtained from Orthosiphon stamineus leaves. Extraction using aqueous solvent enabled a simultaneous extraction of both hydrophilic and lipophilic phenolic compounds. Higher solid concentration leads to higher solution viscosity, bigger particle size, lower moisture content and a less dented surface, which may improve particle flowability. The results suggest that eupatorin and rosmarinic acid are more susceptible to thermal degradation than sinensetin during spray drying. The formulation of 1:9 whey protein to maltodextrin ratio was also found to be more effective, with 86.7% total flavonoids retention compared to other formulations, viz, 1:1 and 9:1

    Generation of Q-switched thulium-doped fiber laser (TDFL) using differentsaturable absorbers

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    A Q-switched Thulium-doped Fiber Laser (TDFL) operating at approximately 2 µm wavelength is successfully generated by using four different saturable absorbers (SAs) which are nitrogen-doped graphene in PVA (NG:PVA), nitrogen-doped graphene in PEO (NG:PEO), single-walled carbon nanotube in PVA (SWCNT:PVA), and high pressure carbon monoxide carbon nanotube in PVA (CNTHiPCO:PVA). The SAs integrated in the cavity were able to provide the real saturable absorption in modulating the intra-cavity losses. SWCNT gives the best results with the highest repetition rate and lowest pulse width of 57.45 kHz and 1.958 nJ correspondingly as compared to the other three SAs

    The impact of Covid-19 pandemic towards socioeconomic wellbeing of rural community in Malaysia

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    The Covid-19 pandemic has impacted the socio-economic well-being of people either in urban or rural areas. The Covid-19 cases and fatalities that concentrated in major urban areas in Malaysia. However, as the pandemic progressed, the rural community faced health vulnerability due to the Covid-19 pandemic threat. Among the significant impacts of the Covid-19 pandemic are income generation, economic activity work, and health vulnerability, especially the rural community involved in rural economic activities such as agriculture and fishery. Therefore, this paper aims to investigate the impact of the Covid-19 pandemic on the socio-economic well-being of rural communities in Malaysia. The case study selection is in Mersing, Pontian and Batu Pahat involving three villages using GIS mapping. The methodology used is quantitative research through a household survey conducted using 182 heads of households based on the economic and social dimensions. The finding reveals that most of the target group experienced a decline in income generation, economic activity restriction, and education issues. Furthermore, there are also decreasing in the economically active population (age 15-60) in the village. As a result, this study is essential in formulating a post-Covid-19 recovery plan regarding socio-economic well-being impacts and the revival of rural community well-being in Malaysia through Geographic Information Systems (GIS) mapping

    Structure integrity analysis on nickel-diamond blade in dicing of hard-brittle ceramic die

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    Dicing operation in cutting hard-brittle ceramic die using nickel-diamond blade causes cracked or chipped die, accelerated tool wear and, ultimately, shortage of blade lifetime. This study aims to analyse the structural integrity of dicing blade in terms of tool wear, surface roughness, microstructure and elements during dicing. The measurements of wear blade on the blade are made by confocal microscope, whereas surface and elemental analyses are carried out with EDX SEM. Results show that the volumetric wear rate of blade is 20%, similar to roughness. The microstructure of the blade changes with occurrence of Aluminium owing to abrasive wear mechanism during cutting

    The impact of Covid-19 pandemic towards the resilience of small medium enterprises (SMEs) in Malaysia

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    The Covid-19 pandemic has impacted the entire world dramatically. The unprecedented Covid-19 pandemic has widely impacted on Malaysia's economy, especially towards the small-scale economic activities related to the small medium enterprises (SMEs). Therefore, this paper aims to determine the impact of the Covid-19 pandemic towards the resilience of SMEs in Johor, Malaysia. The research methodology employed a quantitative method through a survey method via questionnaire sampling of 60 owners involved in SMEs operators across the case study. The research finding indicated that the Covid-19 pandemic had a massive influence on the economy of the majority of SMEs operators, especially on their income generations which average losses in revenue of more than 50 percent during the Covid-19 pandemic compared to 2019. This resulted from the shutdown of their business activities to curb the spread of the Covid-19 pandemic. Other findings highlighted that the government's initiatives to address the economic impact of SMEs yet insufficient to sustain business activities and income generations for instance access to financing facilities, product marketing opportunities and others. Therefore, required immediate initiatives should be made by all the stakeholders to reduce the economic impacts among the SMEs
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