790 research outputs found

    Optimization of injection molding parameter of ti-6al-4v powder mix with palm stearin and polyethylene for the highest green strength by using taguchi method

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    This paper present the Taguchi method of L27 (313) orthogonal array as a tool in optimization of Metal injection molding (MIM) parameters for the highest green strength. Injection pressure, injection temperature, powder loading, mold temperature, holding pressure and injection speed are Parameters to be optimized. Besides those, interaction of the injection pressure, injection temperature and powder loading were studied. The metal powder of Ti-6Al-4V is mixed with binder 60wt% of palm stearin and 40wt% of polyethylene successfully injected at optimum parameter condition: 350 bar of injection pressure, 140oc of injection temperature, 65vol% of powder loading, 50oc of mold temperature, 600 bar of holding pressure, and 10ccm/s of the injection rate. Analysis of variance (ANOVA) for the best signal to noise ratio (S/N) presents the contribution of the parameters to the quality characteristic (green strength). Results show that the mold temperature has highest significant percentage (27.59%) followed by powder loading (15.44%) and injection pressure (12.30%) Nevertheless, the analysis of variance does not show any contribution from interaction

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

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    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

    Design of planar dielectric resonator antenna array at 28 GHz

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    This article presents a planar array of rectangular Dielectric Resonator Antenna operating for 28 GHz applications. The proposed antenna is formed through two stages of designs which are a single element and planar array. It is made up from a ceramic material with a dielectric constant of 10 and mounted on RT/Duroid 5880 with a relative permittivity of 2.2 and a thickness of 0.254 mm. A prospective study using three different configurations of three by three planar array is done in order to obtain the best performance in terms of bandwidth, gain, and cost reduction. Besides that, this study is also conducted for a beam steering capability of each configuration. Finally, the best configuration is proposed for 5G application

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

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    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

    CO₂ adsorption on zeolites and Fe-MOF for carbon capture and storage (CCS)

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    This research focused on the development of suitable materials for capturing and storing CO2 (CCS). Ferum-metal organic framework (Fe-MOF) and zeolite were prepared as adsorbents for the CO2 adsorption process. These adsorbents were characterised by employing X-ray diffraction (XRD) and Fourier Transform Infrared (FTIR) analysers. The adsorptive capacity of CO2 was conducted in an assembled facility containing of a metallic tubular container set up with a pure CO2 gas stream from a cylinder-shaped tank. The performance of these two adsorbents was investigated using two different parameters which are operating pressure and dosage of adsorbents. The exit concentration of CO2 was analyzed periodically using gas chromatography. Based on the FTIR and XRD studies, the findings suggest that the zeolite and Fe-MOF were successfully formed. The optimal adsorption conditions obtained for both adsorbents were 0.3 g of adsorbent dose and 1 bar of operating pressure. In conclusion, zeolite exhibits better performance as a CO2 adsorber due to its higher adsorption capacity than Fe-MOF

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

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    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

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    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

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    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

    Sirtuin Inhibition and Anti-Cancer Activities of Ethyl 2-benzimidazole-5-carboxylate Derivatives

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    New benzimidazoles were synthesized based on the previously identified sirtuin inhibitor BZD9L1. The compounds were screened for their sirtuin (SIRT1, SIRT2 and SIRT3) inhibitory activities. Compound BZD9Q1 was determined to be a pan-SIRT1–3 inhibitor. Furthermore, the proliferation of various cancer cells was inhibited by BZD9Q1. It was shown that BZD9Q1 elicits a cytostatic effect by inducing cell cycle arrest at the G2/M phase while also showing a prominent induction of apoptosis against oral cancer cells
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