Preparation and Characterization of Polypropylene-Natural Rubber/Clay Nanocomposites

In this study, octadecylamine (ODA-MMT) and dodecylamine (DDA-MMT) modified natrium-montmorillonites (Na-MMTs) were used to prepare polypropylene-natural rubber /clay nanocomposites. The products were characterized using Fourier Transform Infrared (FTIR) spectroscopy, X-ray diffraction (XRD), Energy Filtering Transmission Electron Microscopy (EFTEM), Thermogravimetric Analyser (TGA) and tensile measurement. To prepare the nanocomposites, the ODA-MMT and DDA-MMT were blend with polypropylene and natural rubber in the ratio of 70: 30, by using an internal mixer. The study of blending speed, temperature and period shows that under the following blending conditions: 80 r.p.m. of rotor speed, temperature of 180oC and 6 minutes of blending period, the hybrid produced with maximum tensile strength and elongation at break was obtained. The optimum clay content to give maximum tensile strength is 1 php. In order to improve the mechanical properties of the blend, different amount of N, N’-m- phenylenedimaleimide (HVA-2) was blended with PPNR and their properties were also studied by tensile measurement, TGA and dynamic mechanical analysis (DMA). One php of HVA-2 was taken as the optimum concentration to be incorporated in PPNR because it gave the highest tensile improvement. The tensile properties and thermal degradation behaviour of PPNR/clay crosslinked with HVA-2 were then compared with the properties of PPNR/clay which consists of maleic anhydride grafted polypropylene (MAgPP) as a compatibilizer. HVA-2 crosslinked PPNR/clay shows higher tensile strength and elongation at break improvement compared to that of the MAgPP compatibilized PPNR/clay. However, the TGA thermograms of these two systems are very similar. The PPNR/HVA-2/clay nanocomposites were further modified by changing their clay contents. XRD and TEM analyses show that octadecylamine modified montmorillonite (ODA-MMT) and dodecylamine modified montmorillonite (DDA-MMT) produce a mixture of intercalation and flocculation, and of intercalation and exfoliation in the hybrids, respectively. By incorporating 1 and 2 php of ODAMMT into the HVA-2 crosslinked PPNR, the tensile strength of the hybrid increases about 10%. One php of DDAMMT clay loaded in the blend causes 7% of increment in tensile strength. The thermal degradation of both organoclay loaded blends is almost the same as the sample with the low clay content. Increase the modified clay content to 5 php improves the degradation temperature of 20oC

Preparation and Physico-Chemical Characterisation of VPO and V₂O₅/TiO₂ Catalysts

Vanadium-based catalyst plays an important role in petrochemical industry in this study, two types of vanadium-based catalysts were synthesised They are vanadium phosphorus oxide and vanadia-titama catalyst. Vanadium phosphorus oxide catalysts were synthesised via two different precursors

The Investigation On The Barriers Of Green Supply Chain Adoptions Among Smes In Penang: The Role Of Business Strategic Orientation As Moderator

Dengan perkembangan yang pesat dan pertumbuhan industri, pemanasan di seluruh dunia dan penipisan sumber daya alam telah menjadi keprihatinan bagi masyarakat, kerajaan dan industri. With the rapid growth and development of the industries, global warming and depletion of natural resources have become a concern for the society, government and the industry

Synthesis and physico-chemical investigation of vanadium phosphorus oxide catalysts derived from VO(H2PO4)2

Vanadium phosphorus oxide catalysts were prepared via VO(H2P04)2 by using two methods: i) reaction of V204 with σ-H3P04 and ii) reduction of VOP04.2H2O with octan-3-ol. The precursors were calcined in n-butane/air mixture at 673 K for 75 h. These catalysts were characterised by using various techniques, such as BET surface area, XRD, FTIR and SEM

Dialogue: kwodrent x FARMWORK with Lilian Chee

Envelop: kwodrent x farmwork: fabricworks25-3

Factors that influence customer switching behavior in the northern region of peninsular Malaysia’s taxi industry

The purpose of this study is to investigate the relationships between pricing, inconvenience, core service failure, service encounter failure, employee responsiveness, attraction by competitors, change in technology, switching cost, word of mouth and customer switching behavior. Consumers who have the experience using taxi service and ride-sharing service in the Northern Region of Peninsular Malaysia’s which consist of Perlis, Kedah, Penang and Perak were chosen as respondent for this study. A total of 400 questionnaires were distributed to the respondents and 391 were collected back and 387 data is usable. Correlation and multiple regression analysis were chosen as the data analysis methods through Statistical Package of Social Science (SPSS-Version 22) software. The findings of this study shows that pricing, inconvenience, core service failure, service encounter failure, employee responsiveness, attraction by competition, switching cost and word of mouth having significant relationship with customer switching behaviors. In conclusion, the findings of this study suggest that taxi industry should improve their pricing, inconvenience, core service failure, service encounter failure, employee responsiveness, attraction by competition, switching cost and word of mouth factors, in order to reduce switching of the customers

Pseudo-solidification of dredged marine soils with cement - fly ash for reuse in coastal development

The dislodged and removed sediments from the seabed, termed dredged marine soils, are generally classified as a waste material requiring special disposal procedures. This is due to the potential contamination risks of transporting and disposing the dredged soils, and the fact that the material is of poor engineering quality, unsuitable for usage as a conventional good soil in construction. Also, taking into account the incurred costs and risk exposure in transferring the material to the dump site, whether on land or offshore, it is intuitive to examine the possibilities of reusing the dredged soils, especially in coastal development where the transportation route would be of shorter distance between the dredged site and the construction location. Pseudo-solidification of soils is not a novel idea though, where hydraulic binders are injected and mixed with soils to improve the inherent engineering properties for better load bearing capacity. It is commonly used on land in areas with vast and deep deposits of soft, weak soils. However, to implement the technique on the displaced then replaced dredged soil would require careful study, as the material is far more poorly than their land counterparts, and that the deployment of equipment and workforce in a coastal environment is understandably more challenging. The paper illustrates the laboratory investigation of the improved engineering performance of dredged marine soil sample with cement and fly ash blend. Some key findings include optimum dosage of cement and fly ash mix to produce up to 30 times of small strain stiffness improvement, pre-yield settlement reduction of the treated soil unaffected by prolonged curing period, and damage of the cementitious bonds formed by the rather small dosage of admixtures in the soil post-yield. In short, the test results show a promising reuse potential of the otherwise discarded dredged marine soils

Examining the efficacy of the Olweus prevention programme in reducing bullying: the Malaysian experience

AbstractMany countries have adapted or adopted the Olweus Bullying Prevention Programme after it was reported that there was a significant reduction in levels of bullying and being bullied. The positive changes were maintained 20 months after the intervention. The objective of this study was to examine the efficacy of the Olweus prevention programme in reducing bullying in selected schools in Malaysia. This study used an experimental pre-test/post-test comparison including a control group involving six secondary schools. Results showed some indication of the effectiveness of the bully-intervention programme in one of the schools. Intervention at the classroom level showed more positive results

The Influence of Accelerating Entropy Inhomogeneities on Combustor Thermoacoustics

The growing global concern over environmental emissions such as nitrogen oxides and noise sets challenging problems for aero-propulsion engineers. Acoustic waves generated by unsteady combustion not only contribute towards the overall noise transmission, but may also cause thermoacoustic instability in combustors, particularly those designed for low NOx emissions. Combustion noise is generated by unsteady combustion – either by the direct generation of acoustic waves or indirectly by the creation of entropy waves. Entropy waves by themselves are silent, but when accelerated, such as through the combustor exit, they create further acoustic waves known as entropy noise. This thesis aims to study transmitted and reflected combustion noise. Current predictions for noise transmission often assume that the wavelengths of the flow perturbations are large compared to the combustor length, known as the compact assumption. We will develop predictions for finite-length combustors accurate to first-order in frequency. The effect of the interaction between an oscillating shock wave with combustion noise is also studied analytically. The predictions agree with data from numerical simulations. Combustion acoustics reflected at the combustor exit may go on to interfere with the combustion process, setting up a feedback mechanism that may lead to thermoacoustic instability. A modified combustor model is presented to study the effect of dissipation and dispersion of entropy waves on the instability, and it was found that the extent of dissipation or dispersion not only plays a significant role on whether instability occurs, but also determines the dominant frequency of oscillations. Furthermore, analytical and numerical investigations suggest that entropy waves are convected with the flow undissipated, and that modelling improvements may be made to take entropy dispersion into account. The findings in this work provide better tools to understand indirect combustion acoustics and to analyse their importance in both transmitted combustion noise and the thermoacoustic instability experienced by low NOx combustors