161 research outputs found

    Chemical Stabilization of Amorphous Peat Using Cement and Fly Ash at Different Water Additive Ratios

    Get PDF
    Peat is a very problematic soil as it is poor in strength. However, previous researchers have proven that the compressive strength of peat can be improved by using various methods of soil improvement including chemical stabilization method. In this study, cement and fly ash and lime were additives used and were mixed with amorphous peat at various water additive ratios. To replicate actual stabilization on site, water additive ratio is proposed as to allow stabilization to be performed at natural water content of the peat. Peat samples were collected from Kampung Endap, Samarahan and mixed at its natural moisture content with cement and with fly ash and lime at different water additive ratios of 3.0, 3.5, 4.0, 4.5 and 5.0. The compressive and bearing strengths of the samples were obtained by the unconfined compressive strength (UCS) test and California Bearing Ratio (CBR) test respectively. The results of the study have shown that there is marginal strength gained after 28 and 56 days of air curing period. The peat samples stabilized with cement at 3.5 water additive ratio recorded the highest value with UCS value of 69.48 kPa after 56 days of curing and 0.52 % for CBR test after 28 days curing period. These strength values obtained are lower compared to published data from previous studies. Different technique of mixing in the laboratory that is mixing peat at its natural water content with varied amount of additives at selected water additive ratio as opposed to mixing at maximum dry density and optimum moisture content that is mostly performed in laboratory contributes to the outcome. However, this study has proven that there is an increase in compressive and bearing strengths of stabilized peat in its natural water content compared to original peat without stabilizer

    Chemical Stabilization of Amorphous Peat Using Cement and Fly Ash at Different Water Additive Ratios

    Get PDF
    Peat is a very problematic soil as it is poor in strength. However, previous researchers have proven that the compressive strength of peat can be improved by using various methods of soil improvement including chemical stabilization method. In this study, cement and fly ash and lime were additives used and were mixed with amorphous peat at various water additive ratios. To replicate actual stabilization on site, water additive ratio is proposed as to allow stabilization to be performed at natural water content of the peat. Peat samples were collected from Kampung Endap, Samarahan and mixed at its natural moisture content with cement and with fly ash and lime at different water additive ratios of 3.0, 3.5, 4.0, 4.5 and 5.0. The compressive and bearing strengths of the samples were obtained by the unconfined compressive strength (UCS) test and California Bearing Ratio (CBR) test respectively. The results of the study have shown that there is marginal strength gained after 28 and 56 days of air curing period. The peat samples stabilized with cement at 3.5 water additive ratio recorded the highest value with UCS value of 69.48 kPa after 56 days of curing and 0.52 % for CBR test after 28 days curing period. These strength values obtained are lower compared to published data from previous studies. Different technique of mixing in the laboratory that is mixing peat at its natural water content with varied amount of additives at selected water additive ratio as opposed to mixing at maximum dry density and optimum moisture content that is mostly performed in laboratory contributes to the outcome. However, this study has proven that there is an increase in compressive and bearing strengths of stabilized peat in its natural water content compared to original peat without stabilizer

    Dengue fatality prediction using data mining

    Get PDF
    Dengue fever, a mosquito-borne tropical disease caused by the dengue virus is life-threatening. In Malaysia, although necessary control measures have been carried out, the number of dengue fever cases keeps increasing. Among the measures, dengue vector control appears to be the most effective way to control the spread of the dengue virus particularly in Malaysia. The aim of this research is to study the current implementation of dengue outbreak control in Malaysia and predict dengue fever cases using data mining techniques. Real data on dengue fever and weather are collected from the Ministry of Health in its Perak Tengah district office and Perak Meteorological office respectively. Different data mining classification techniques are applied onto these data with the performance of each technique is measured. The results highlight the best performance among techniques used.Keywords: data mining; prediction; dengue; classification

    The Use of GPR in Delineating an Iron Sand Boundary and the Determination of Its Electromagnetic Wave Velocity: A Case Study in Jepara, Central Java

    Get PDF
     Exploring the vertical extent of iron sand deposit is challenging as conventional geophysical methods (electrical resistivity, geomagnetic, and seismic refraction) are inappropriate and unsuccessful in delineating the iron sand deposit from the bedrock. Ground-penetrating radar (GPR) offers a solution to the above problem as radar is not affected negatively by the physical properties of iron sand. In the year 2003, a RAMAC's GPR survey was carried out in the coast of Bayuran in the Regency of Jepara, Central Java to map the distribution of sub-bottom iron sand. The sand is highly magnetic. The survey used 100 MHz antennas. The survey is also complimented by a novel method in determining the electromagnetic (EM) wave velocity of iron sand. Combination of reflection profiling and CMP sounding was deployed. Results of CMP sounding were processed using CMP-semblance analysis that produces the RMS velocity in velocity-time spectra. The RMS velocity is then converted to interval velocity using Dix's formula and is found to be about 135 mm/ns. Meanwhile, combination of magnetic susceptibility, relative permittivity, and dissipation factors produces radiowaves velocity of iron sand as a function of frequency. The velocities of radiowaves estimated from laboratory match that estimated from CMP analysis

    Development Of Control Circuit For Single Phase Inverter Using Atmel Microcontroller.

    Get PDF
    This paper presents the development of control circuit for single phase inverter using Atmel microcontroller. The attractiveness of this configuration is the elimination of a microcontroller to generate sinusoidal pulse width modulation (SPWM) pulses

    A Review on Carbon Fiber Reinforced Polymer as Wrapping Structures For Pipeline

    Get PDF
    To maintain the continuous product flow in the pipe, the durability of the pipe structure is achieved through pipe insulation. The composite material will be used as the main material, since it may have the combined characteristics of the constituents or have substantially different properties than the individual constituents. Replacing the damaged pipe with a new one will not only consume high cost but also will create a complication for product flow. As to alleviate such situations this research focusses on using the carbon fiber as the wrapping material. To identify the suitable design and optimization of laminated carbon fiber on piping systems, the defect, leakage and imperfection on pipe should be identified. The effect of different laminate optimization through Classical Laminate Theory CLT and experimental data too need to be considered as it changes the mechanical properties of the composite material. The microstructure of the composite too will be validated as an extra reference for the theoretical and experimental data on its effect in the microstructure after the loadin

    A Review on Carbon Fiber Reinforced Polymer as Wrapping Structures For Pipeline

    Get PDF
    To maintain the continuous product flow in the pipe, the durability of the pipe structure is achieved through pipe insulation. The composite material will be used as the main material, since it may have the combined characteristics of the constituents or have substantially different properties than the individual constituents. Replacing the damaged pipe with a new one will not only consume high cost but also will create a complication for product flow. As to alleviate such situations this research focusses on using the carbon fiber as the wrapping material. To identify the suitable design and optimization of laminated carbon fiber on piping systems, the defect, leakage and imperfection on pipe should be identified. The effect of different laminate optimization through Classical Laminate Theory CLT and experimental data too need to be considered as it changes the mechanical properties of the composite material. The microstructure of the composite too will be validated as an extra reference for the theoretical and experimental data on its effect in the microstructure after the loadin

    Microcontroller Implementation Of Single Phase Inverter Switching Strategies.

    Get PDF
    This paper presents the practical microcontroller implementation of single phase inverter switching strategies

    Design And Development Of High Frequency High Power Transformer For Renewable Energy Application.

    Get PDF
    This paper presents a design and fabrication of a high frequency transformer for 5 kW power rating. Within an operating frequency of 25 kHz, a MnZn P type core has been utilized. Two set of E-E geometry cores had to be stacked in order to achieve rhe calculated 64.14 cm4 of the W^Ac volume. Test and validation of the designed shows that the prototype designed tansformer had proven to be very compact, higher fill factor, smaller in size, lighter in weight if compared to other winding approaches which utilizing copper round wires. The measured overall losses of the transformer itself were remain below the expected value of 32.974 W. The efficiency of the transformer was found to be at 93% average. Overall test results also show that the design and implementation of this high frequency power transformer is applicable especially fo renewable energy system.

    Effect of number of baffles on flow and pressure drop in a shell side of a shell and tube heat exchangers

    Get PDF
    The effect of number of baffles on flow and pressure drop on a shell side of shell-andtube heat exchangers was studied. In the present study, a set of CFD simulations using FLUENT version 17.0 from ANSYS were used to analyze the flow in the single shell and single tube pass heat exchangers consists of 20 mm diameter of tubes in staggered configuration with a variable number of baffles. The simulations were undertaken to inform on how the fluid flowed within the shell side of shell-and-tube heat exchangers. The results show that the variable number of baffles and baffle spacing in a heat exchanger strongly affect the flow pattern and pressure drop. This is consistent with other published data
    corecore