Short-Term Ability of Concrete Containing Palm Oil Fuel Ash Exposed to Sodium Sulphate

Uncontrolled palm oil waste disposal can lead to an environmental problem, and recycling the waste can assist in reducing the disposal problem. On another side, concrete exposed to sulphate normally will lose its strength after some time. Replacing cement with palm oil fuel ash (POFA) can lower the disposal issue and help reduce the concrete from strength losses. The main objective of this study is to investigate the short-term effects on the strength of concrete containing POFA exposed to sulphate solution. The POFA was prepared by drying in an oven for 24 hours at 105°C and sieved passing through a 300 μm sieve. Then, the POFA had been refined using ball mills for two hours. The percentage of POFA as cement replacement used in this study is 10%, 20% and 30% by volume of cement. Two types of specimens were prepared, i.e., cube specimen (100 mm × 100 mm × 100 mm) and prism specimen (500 mm × 100 mm × 100 mm) that fully immersed in water and 3.5% sulphate solutions. Density test, water absorption test, compression strength test and flexural strength test were conducted after 7 and 28 days of the exposure period. A total of 144 specimens was subjected to these tests. The experiments show that concrete with 10% replacement of POFA had a higher slump value, while the density test showed that the 10% POFA mixture had a lower density than the other specimens. Furthermore, the water absorption test showed that more POFA in concrete contributes to higher water absorption when exposed to sulphate solution compared to water. In conclusion, the compressive strength and flexural strength test recorded replacement of 10% POFA is the highest strength of concrete containing POFA exposed to sulphate solution and water

Short-Term Ability of Concrete Containing Palm Oil Fuel Ash Exposed to Sodium Sulphate

Uncontrolled palm oil waste disposal can lead to an environmental problem, and recycling the waste can assist in reducing the disposal problem. On another side, concrete exposed to sulphate normally will lose its strength after some time. Replacing cement with palm oil fuel ash (POFA) can lower the disposal issue and help reduce the concrete from strength losses. The main objective of this study is to investigate the short-term effects on the strength of concrete containing POFA exposed to sulphate solution. The POFA was prepared by drying in an oven for 24 hours at 105°C and sieved passing through a 300 μm sieve. Then, the POFA had been refined using ball mills for two hours. The percentage of POFA as cement replacement used in this study is 10%, 20% and 30% by volume of cement. Two types of specimens were prepared, i.e., cube specimen (100 mm × 100 mm × 100 mm) and prism specimen (500 mm × 100 mm × 100 mm) that fully immersed in water and 3.5% sulphate solutions. Density test, water absorption test, compression strength test and flexural strength test were conducted after 7 and 28 days of the exposure period. A total of 144 specimens was subjected to these tests. The experiments show that concrete with 10% replacement of POFA had a higher slump value, while the density test showed that the 10% POFA mixture had a lower density than the other specimens. Furthermore, the water absorption test showed that more POFA in concrete contributes to higher water absorption when exposed to sulphate solution compared to water. In conclusion, the compressive strength and flexural strength test recorded replacement of 10% POFA is the highest strength of concrete containing POFA exposed to sulphate solution and water

Car position and orientation based driving skill metric for analytical driving skill index evaluator

This paper proposes an improved driving skill metric incorporating car-track deviation angle and car position off-set correction agility. The main advantage of the method is which it provides more accurate since this research is using more variables in the formulation for the skill metric compared to the old metric by using the same sample group of subjects. This paper reports nearly an average of 95 of improvement for the new skill metric estimation accuracy. The analysis further reveals the metric also has better driving skill index estimation consistency. The proposed method herein offers a means for characterizing driving skill in response to car-track input information and improving the intelligent behaviours of car support system

Traceability in Digital Forensic Investigation Process

Digital forensic is part of forensic science that implicitly covers crime that is related to computer technology. In a cyber crime, digital evidence investigation requires a special procedures and techniques in order to be used and be accepted in court of law. Generally, the goals of these special processes are to identify the origin of the incident reported as well as maintaining the chain of custody so that the legal process can take its option. Subsequently, the traceability process has become a key or an important element of the digital investigation process, as it is capable to map the events of an incident from difference sources in obtaining evidence of an incident to be used for other auxiliary investigation aspects. Hence, this paper introduces a trace map model to illustrate the relationship in the digital forensic investigation process by adapting and integrating the traceability features. The objective of this integration is to provide the capability of trace and map the evidence to the sources and shows the link between the evidence, the entities and the sources involved in the process, particularly in the collection phase of digital forensic investigation framework. Additionally, the proposed model is expected to help the forensic investigator in obtaining accurate and complete evidence that can be further used in a court of law

Tracebility in Digital Forensic Investigation Process

Digital forensic is part of forensic science that implicitly covers crime that is related to computer technology. In a cyber crime, digital evidence investigation requires a special procedures and techniques in order to be used and be accepted in court of law. Generally, the goals of these special processes are to identify the origin of the incident reported as well as maintaining the chain of custody so that the legal process can take its option. Subsequently, the traceability process has become a key or an important element of the digital investigation process, as it is capable to map the events of an incident from difference sources in obtaining evidence of an incident to be used for other auxiliary investigation aspects. Hence, this paper introduces a trace map model to illustrate the relationship in the digital forensic investigation process by adapting and integrating the traceability features. The objective of this integration is to provide the capability of trace and map the evidence to the sources and shows the link between the evidence, the entities and the sources involved in the process, particularly in the collection phase of digital forensic investigation framework. Additionally, the proposed model is expected to help the forensic investigator in obtaining accurate and complete evidence that can be further used in a court of la

Robust Input Shaping for Sway Control of an Overhead 3D Crane

This paper presents a robust input shaping control of an overhead 3D crane. Control of a crane in the presence of wind disturbance during payload hoisting is extremely challenging, as hoisting with wind disturbance causes high unwanted payload sway, which makes payload positioning difficult to achieve. Two robust input shaping techniques are presented, the zero vibration derivative-derivative (ZVDD) and extra insensitive (EI) shapers. Simulations using a nonlinear 3D overhead crane model were performed and the performances of the two robust input shapers are compared. In these investigations a wind disturbance force of magnitude 0.3 N is considered for the robustness test, in addition different payload mass were tested. It is predicted that the method can be very useful in reducing the complexity of closed-loop controllers for both tracking and sway control

Enhanced meshfree RPIM with NURBS basis function for analysis of irregular boundary domain

Radial Point Interpolation Method (RPIM) has become a powerful tool to numerical analysis due to its ability to provide a higher-order approximation function with the Kronecker delta property, by which the field nodes can be fitted exactly. However, one of the major drawbacks of RPIM is the inefficiency in handling irregular domain problems. This paper presents an enhanced RPIM formulation that employs Non-Uniform Rational B-Splines (NURBS) basis functions to represent the exact geometry of the boundary domain. The NURBS is a mathematical model which provides an efficient and numerically stable algorithm to exactly represent all conic sections in engineering modelling. Taking advantage of the flexibility and adaptivity of RPIM approximation and the accuracy of geometric representations by NURBS, this new method is able to improve geometry accuracy and flexibility in numerical analysis, thus providing a better and more rational approach to analyze irregular domain problems. Numerical problem of steady heat transfer considering curved beam is presented to verify the validity and accuracy of the developed method. The essential boundary condition can simply be imposed using direct imposition as in Finite Element Method (FEM). The result shows that the RPIM/NURBS achieved the converged solution much faster than conventional RPIM and FEM, with the number of nodes required only less than 200 for an error of less than 0.01%. This shows the potential of the developed method as a powerful numerical technique for future development

Study of factors influencing construction delays at rural area in Malaysia

Construction is one of an important industry which contributes to the economic growth in Malaysia. However, it has been revealed that 79.5 percent and 66.7 percent of the public and private projects were not completed within the time specified in the contracts out of 359 projects in Malaysia. Therefore, the purpose of this study is to investigate the delay factor caused project delay at rural area. A 5-points Likert scale questionnaire survey were answered by 111 respondents which having experience with rural construction project. The questionnaire data were analysed by using Relative Importance Index (RII). Five top factors were determined from this study based on their RII values which are improper construction method implemented by contractor, weather condition, difficulties in providing delivery to site, breakdown of site equipment, and poor qualification of contractor’s technical staffs

Effect of oil palm planting materials, rainfall, number of male inflorescence and spikelet on the population abundance of oil palm pollinator, Elaeidobius Kamerunicus faust (Coleoptera: Curculionidae)

Elaeidobius kamerunicus is the main insect pollinator of oil palm and was first introduced to Malaysia in the year of 1980s. This introduction had increased the oil palm yield production. However, the yield production has obviously declined lately. There are several factors that contributing to the declined and most said is because of the E. kamerunicus population itself. As such, a study to determine the population abundance of E. kamerunicus on different oil palm planting materials was done at Ladang FELDA in Jengka, Pahang, Malaysia from May 2016 to April 2017. A total of nine spikelets, three each from top, middle and bottom section of male inflorescence which were systematically selected prior to data collection, were cut off early in the morning and brought back to Centre for Insect Systematics, UKM for E. kamerunicus counts. The mean population abundance of E. kamerunicus per ha for both oil palm clones and D×P were 20463 ± 3528 and 11079 ± 2135 weevils per ha, respectively. Based on previous studies in Malaysia and elsewhere, the E. kamerunicus populations in this plantation are adequate to pollinate the female inflorescence. Oil palm clones has higher number of spikelet due to uniformity of the plantlets and the number of male inflorescence showed positively correlated with the population abundance of E. kamerunicus per ha, suggesting that these factors were favorable for E. kamerunicus activities. However, further study is needed to determine the relationship between E. kamerunicus population on different oil palm planting materials and the fruit set

Dielectric spectroscopy on mixture of rice husk, rice husk ash and rice bran from 4 Hz to 1 MHz

In this study, mixtures of rice husk/rice husk ashes (RHA) with RB on different ratios were prepared. Dielectric permittivity (ε'), loss factor (ε") and AC conductivity (σ') were measured in the frequency range of 4 Hz to 1 MHz in ambient temperature. Results for mixture of RHA and RB indicate that a dipolar relaxation occurring between 103 - 105 Hz and the peak is depressed and shifted to lower frequency as the RB content increases in the mixture. Moreover, AC conductivity decreases as the RB content increase. This may attributed to production of natural oil content from RB. In contrast, a dielectric characteristic for RH is generally not affected by the RB contents. This study explore dielectric characteristic of mixture between RH/RHA and RB in low frequency range because lack of literature is reported on low frequency response. Additionally, the potential application of RH/RHA and RB could be explored in effort to diminish waste disposal and enhance environmental protection