Critical gap analysis of merging sections at Kuala Lumpur middle ring road

At merging sections, drivers normally slow down and sometimes need to stop while seeking a suitable gap before merging with the mainstream. Thus, there will always be several observed rejected gaps and an accepted gap which can be used to determine the smallest average gap, so-called critical gap. This study was carried out to determine critical gap values at selected merging sections at the Jalan Tun Razak and the DUKE Expressway uses the Maximum Likelihood method. Data were collected by using videotaping method and the gap acceptance data were extracted for analysis. A gap acceptance event at highway merging sections in this study was redefined due to unavailability of stopping vehicles at the ramp junction. Therefore, the gap data were estimated starting from a ramp’s vehicle passing the end of gore marking to where it merges with the mainstream. The analysis of the critical gap takes into consideration accepted gaps greater than 5 seconds to avoid forced entry due to lead impedance of successive vehicles on mainstream. The critical gap values obtained in this study, according to vehicle classification were ranged between 4.5 to 5.0 seconds, which are slightly smaller if compared to critical gap values for particularly left turn from minor movement at priority junction of the Arahan Teknik (Jalan) 11/87 and the United States Highway Capacity Manual 2000. The findings shall help to study driving behavior of local drivers, especially at priority control facilities such as merging sections

Mechanistic insight of the formation of visible-light responsive nanosheet graphitic carbon nitride embedded polyacrylonitrile nanofibres for wastewater treatment

Effective capture and in situ photodegradation of methylene blue (MB) dye is a promising technique to purify wastewater containing MB. With recently elicited ripples of discovery on graphitic carbon nitride (g-C3N4), this study investigates the performance of g-C3N4 on photodegradation of MB. In this study, polyacrylonitrile (PAN) nanofibres embedded with g-C3N4 photocatalyst was successfully prepared using electrospinning technique which produced liquid-permeable self-supporting photocatalytic nanofibre mats that can be handled easily. Different configurations of g-C3N4 were synthesised, bulk g-C3N4 (bg-C3N4) and nanosheets g-C3N4 (nsg-C3N4) from urea using a green facile template-free method. Effective photocatalytic activity of the g-C3N4 nanofibres was confirmed by 97.3% degradation of MB under visible light irradiation. Photodegradation of MB in aqueous solution by g-C3N4 nanofibres predominantly attributed to the synergetic effects of MB adsorption by PAN nanofibres and photocatalytic degradation of MB by g-C3N4 photocatalyst. This present work not only presents the simplest ecofriendly and economical approach to fabricate g-C3N4 nanofibre photocatalyst, but also paves new opportunities for this advanced photocatalyst as great potential in environmental remediation for treatment of industrial MB wastewater

Correlation Between Cutting Force and Residual Stress in Dry End-Milling of Inconel HX

Residual stress in the end-milled subsurface can significantly affect the fatigue performance of end-milled material. In the end-milling process, the generation of residual stress is extremely complex, which is closely related to the spindle speed, feed per tooth and cutting force. Thus, it is crucial to elucidate the influence of spindle speed and feed per tooth on cutting force and residual stress, also the correlation between cutting force and residual stress in terms of spindle speed and feed per tooth. According to this, dry end-milling of Inconel HX was performed by climb-milling using Kennametal KYS40 solid ceramic end-mill. From this experimental test, cutting force and residual stress showed a U-shaped relationship with the increase of spindle speed, while cutting force and residual stress showed a linear relationship with the increase of feed per tooth. Furthermore, for low cutting force and residual stress, the focus should be on choosing the optimum combination of spindle speed (21,400 to 24,100 rpm) and feed per tooth (0.014 to 0.016 mm/tooth)

Correlation Between Cutting Force and Residual Stress in Dry End-Milling of Inconel HX

Residual stress in the end-milled subsurface can significantly affect the fatigue performance of end-milled material. In the end-milling process, the generation of residual stress is extremely complex, which is closely related to the spindle speed, feed per tooth and cutting force. Thus, it is crucial to elucidate the influence of spindle speed and feed per tooth on cutting force and residual stress, also the correlation between cutting force and residual stress in terms of spindle speed and feed per tooth. According to this, dry end-milling of Inconel HX was performed by climb-milling using Kennametal KYS40 solid ceramic end-mill. From this experimental test, cutting force and residual stress showed a U-shaped relationship with the increase of spindle speed, while cutting force and residual stress showed a linear relationship with the increase of feed per tooth. Furthermore, for low cutting force and residual stress, the focus should be on choosing the optimum combination of spindle speed (21,400 to 24,100 rpm) and feed per tooth (0.014 to 0.016 mm/tooth)

Evaluation on the Potential of Hot Spring as Nature Tourism Attraction in Lojing Highlands, Kelantan, Peninsula Malaysia

Natural hot springs are a common occurrence in Malaysia. These natural hot springs occur when water seeps into the earth and is heated by magma and pressure causes the water to rise again as a heated pool or hot springs. Some locals believe that these natural hot springs have curative effects and can cure skin ailments such as rashes, pimples and fungi infections. Whether this is true or not remains to be scientifically proven, but these places have become a magnet for tourists and those seeking healing. Some of Malaysia’s natural hot springs have developed into modern tourists’ attractions with shops, rest houses, restaurants and changing rooms built nearby to accommodate visitors who are interested by this natural phenomenon and the best example is the Poring Hot Springs, in Ranau, Sabah. Consequently, the objective of this paper is to briefly highlight the potential of Lojing’s hot springs as nature tourism attraction for the state of Kelantan. This paper provides a broad insight into the demand for services and facilities, location and characteristics of Lojing’s geothermal and natural mineral water resources, the opportunities available to expand and establish new facilities and an indication of the success of Sabah’s developments with the potential to be replicated in Lojing. Based on the content analysis done using Leximancer, it is apparent that Lojing’s hot spring requires intervention in terms of strategies that aimed at increasing tourist satisfaction. It is suggested that the theme “leisure” to be concentrated as the pull factor for Lojing hot spring-based tourism

Impact of Long-Term Forest Enrichment Planting on the Biological Status of Soil in a Deforested Dipterocarp Forest in Perak, Malaysia

Deforestation leads to the deterioration of soil fertility which occurs rapidly under tropical climates. Forest rehabilitation is one of the approaches to restore soil fertility and increase the productivity of degraded areas. The objective of this study was to evaluate and compare soil biological properties under enrichment planting and secondary forests at Tapah Hill Forest Reserve, Perak after 42 years of planting. Both areas were excessively logged in the 1950s and left idle without any appropriate forest management until 1968 when rehabilitation program was initiated. Six subplots (20 m × 20 m) were established within each enrichment planting (F1) and secondary forest (F2) plots, after which soil was sampled at depths of 0–15 cm (topsoil) and 15–30 cm (subsoil). Results showed that total mean microbial enzymatic activity, as well as biomass C and N content, was significantly higher in F1 compared to F2. The results, despite sample variability, suggest that the rehabilitation program improves the soil biological activities where high rate of soil organic matter, organic C, N, suitable soil acidity range, and abundance of forest litter is believed to be the predisposing factor promoting higher population of microbial in F1 as compared to F2. In conclusion total microbial enzymatic activity, biomass C and biomass N evaluation were higher in enrichment planting plot compared to secondary forest. After 42 years of planting, rehabilitation or enrichment planting helps to restore the productivity of planted forest in terms of biological parameters

Quantum key distribution in terms of the Greenberger-Horne-Zeilinger state: multi-key generation

In this paper, we develop a quantum key distribution protocol based on the Greenberger-Horne-Zeilinger states (GHZs). The particles are exchanged among the users in blocks through two steps. In this protocol, for three-particle GHZs three keys can be simultaneously generated. The advantage of this is that the users can select the most suitable key for communication. The protocol can be generalized to $N$ users to provide $N$ keys. The protocol has two levels for checking the eavesdroppers. Moreover, we discuss the security of the protocol against different attacks.Comment: 10 Page, no figures. Comments are most welcom

Parameter optimization of debinding injection moulded Ti-6Al-4V mix with palm stearin and polyethylene

Debinding process of injection moulded Ti-6Al-4V feedstock was divided into two parts: solvent debinding process to eliminate palm stearin (PS) and thermal pyrolysis to eliminate polyethylene (PE). Solvent debinding process used heptane at optimum temperature, 60°C to remove PS binder completely as temperature is the only parameter that can be optimized. Thermal pyrolysis parameters for removal of PE binder from the injected 65vol% Ti-6Al-4V feedstock have been optimized by using Taguchi method. Heating rate, temperature and time were the selected factors during experiment to be applied in the L9(34) Taguchi orthogonal array (OA) to find the best set of parameters to produce highest density of brown part. Thermal pyrolysis process was done at optimum parameters: heating rate: 5°C/min; temperature: 510°C; and time: 90 minutes. Analysis of Variance (ANOVA) was employed to find the best signal to noise ratio (S/N) to express the contribution of the factors towards quality characteristic. Based on the results, heating rate has the greatest contribution (54.63%), followed by duration time of thermal pyrolysis (24.40%) and temperature (19.25%)

A Review of Forensic Entomology Cases at Ipoh Hospital and Hospital Universiti Kebangsaan Malaysia for the Year 2003

Forensic entomology was utilized to determine the postmortem interval of eleven forensic cases sentfor autopsy examination at Ipoh Hospital and Hospital University Kebangsaan Malaysia between of Januaryto December 2003. Sixth species of sarcosaprophagous flies: Chrysomya megacephala, Chrysomya rufifacies,Chrysomya villeneuvi, Chrysomya nigripes, Synthesiomya nudiseta and a sarcophagid fly were found amongthe maggot specimens received by the Forensic Entomology Laboratory, Department of Parasitology &Medical Entomology, Universiti Kebangsaan Malaysia. Those maggots were collected from dead bodiesfound among others in wrapped in gunny bags, around water tank, hanged with black nylon clothes, insidehome, beside road, drowning in lombong and an estate. Ch. megacephala was the main species found in eightcases examined. Postmortem Interval (PMI) estimated from the cases varied from one day to 10 days