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Alinda Samsuri Mohd Nor Latif Mohd Razali Shamsuddin Fairous Salleh Maratun Najiha Abu Tahari Tengku Shafazila Tengku Saharuddin Norliza Dzakaria Mohd Ambar Yarmo 《International Journal of Hydrogen Energy》2021,46(48):24831-24844
Temperature programmed reduction (TPR) analysis was applied to investigate the chemical reduction progression behavior of molybdenum oxide (MoO3) catalyst. The composition and morphology of the reduced phases were characterized by X-ray diffraction spectroscopy (XRD), X-ray photoelectron spectroscopy (XPS), and field emission scanning electron microscopy (FE-SEM). The reduction progression of MoO3 catalyst was attained with different reductant types and concentration (10% H2/N2, 10% and 20% CO/N2 (%, v/v)). Two different modes of reduction process were applied. The first approach of reduction involved non-isothermal mode reduction up to 700 °C, while the second approach of reduction involved the isothermal mode reduction for 60 min at 700 °C. Hydrogen temperature programmed reduction (H2-TPR) results showed the reduction progression of three-stage reduction of MoO3 (Mo6+ → Mo5+ → Mo4+ → Mo0) with Mo5+ and Mo4+. XRD analysis confirmed the formation of Mo4O11 phase as an intermediate phase followed by MoO2 phase. After 60 min of isothermal reduction, peaks of metallic molybdenum (Mo) appeared. Whereas, FESEM analysis showed porous crater-like structure on the surface cracks of MoO2 layer which led to the growth of Mo phase. Meanwhile, the reduction of MoO3 catalyst in 10% carbon monoxide (CO) showed the formation of unstable intermediate phase of Mo9O26 at the early stage of reduction. Furthermore, by increasing 20% CO led to the carburization of MoO2 phase, resulted in the formation of Mo2C rather than the formation of metallic Mo, as confirmed by XPS analysis. Therefore, the presented study shows that hydrogen gave better reducibility due to smaller molecular size, which contributed to high diffusion rate and achieved deeper penetration into the MoO3 catalyst compared to carbon monoxide reductant. Hence, the reduction of MoO3 in carbon monoxide atmosphere promoted the formation of Mo2C which was in agreement with the thermodynamic assessment. 相似文献
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Lee Suan Chua Norliza Abdul Latiff Sze Yean Lee Chew Tin Lee Mohamad Roji Sarmidi Ramlan Abdul Aziz 《Food chemistry》2011
Both total phenolic content (TPC) and total flavonoid content (TFC) of Labisia pumila extracts were determined spectrophotometrically. L. pumila leaves extracted in 60% methanol (MeOH) were fractionated on C18 cartridge and the antioxidant property of each fraction was determined by measuring free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity. The 40% MeOH fraction exhibited the highest scavenging activity. Nine flavonols (quercetin, myricetin and kaempferol), two flavanols (catechin and epigallocatechin) and nine phenolic acids were identified from this active fraction by UPLC–ESI-MS/MS, and confirmed by comparison with the mass spectra of standard aglycones, theoretical fragments generated from MS Fragmenter software, and literature values. 相似文献
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F. Azzatul M.H.A. Jahurul J. Norliza M.R. Norazlina M. Hasmadi Shaarani Md. Sharifudin Patricia Matanjun Jau-Shya Lee A. Shihabul Noorakmar Ab. Wahab 《International Journal of Food Science & Technology》2021,56(4):1574-1581
The search for hard fats is increasing by the day due to their demand for industrial purposes. Rambutan seed fat (RSF) was fractionated prior to investigate the melting and crystallisation behaviours, triacylglycerols (TAGs), and morphology using different chromatographic and thermal techniques. The increasing trends were observed for high-melting symmetrical monounsaturated TAGs such as 1,3-distearoyl-2-oleoyl-glycerol and 1-palmitoyl-3-stearoyl-2-oleoyl-glycerol in both solid fractions upon fractionation. The solid fractions (F1-S) and (F2-S) exhibited small peaks towards low melting area and big peaks towards high melting area with the offset temperatures of 35.29–48.75 °C and 43.58–52.70 °C with significantly higher enthalpies (93.49 and 105.13 J g−1) upon fractionation. F2-S showed the densely packed microstructure compared to that of crude RSF and F1-S. Based on the thermal behaviours as well as morphology of RSF fractions, cocoa butter improver could be prepared that has the potential to be utilised in chocolate manufacturing in tropical countries. 相似文献
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NorlizaKassim 《数码世界》2003,2(11):43-44
你最近一次收到那些不受欢迎的E-mail或SMS是什么时候?我猜大约在过去的24小时之内吧。虽然从收件箱中删除那些E—mail或SMS很容易,但有时它们仍会让人感到困扰,你可能会对自己说”如果我让他不要再发了,还有成百个象他这样的会继续发,然而,我对此从不感兴趣!” 相似文献
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W M Wan Norliza I Siti Raihan J Azlyn Azwa M Ibrahim 《Contact lens & anterior eye》2006,29(4):165-167
PURPOSE: To report a case of scleral melting noted 16 years after pterygium excision with postoperative adjuvant topical Mitomycin C (MMC). METHOD: Case report. RESULTS: A 61-year-old Malay gentleman underwent right nasal pterygium excision using bare sclera technique followed by topical MMC 0.1% for a week, 16 years ago. He was noted to have a right nasal scleral thinning with calcified plaque and granuloma. He was successfully treated conservatively without further progression of the scleral melting. CONCLUSION: Long-term complication of pterygium excision with adjuvant topical Mitomycin C may occur. The case shows that early detection and recognition of the complication can be sight saving. 相似文献
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Kawther M Musthaf Azura Hamzah Ooi Wei Ling Ahmad Haziq Aiman Rosol Norliza Mohame Sulaiman Wadi Harun 《光电子快报》2024,20(6):321-329
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Abdul Latif Ahmad Suzylawati Ismail Norliza Ibrahim Subhash Bhatia 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2003,78(9):971-978
Palm oil mill effluent (POME) was pretreated to remove suspended solids and residual oil. The processes used were flocculation, solvent extraction, adsorption and membrane separation. Flocculation was used to remove suspended solids, and solvent extraction and adsorption processes were used to remove residual oil. Membrane separation was subsequently applied to remove any residual suspended solids and oil remaining after the pretreatments. The solvent extraction and adsorption processes were operated on a batch basis whereas membrane separation was performed in continuous mode. The treatment efficiency of the processes was measured as percentage removal of suspended solids and oil respectively. The optimum values of the process parameters obtained in the flocculation process were an alum dosage of 4000 mg dm?3, mixing speed of 150 rpm for 1 h and sedimentation time of 270 min, resulting in 93% suspended solids removal. In the solvent extraction process, a 95% reduction in residual oil was obtained using n‐hexane as a solvent with 20 min of mixing at 200 rpm. The ratio of solvent to POME was 6:10 and carried out at pH 9. In the batch adsorption process, an 88% reduction in residual oil was obtained at a mixing speed of 100 rpm for 1 h, pH 9 and an adsorbent dosage of 300 g dm?3. In membrane separation processes, GH and CE(GH) membranes gave 63% and 49% reductions in suspended solids and residual oil respectively at pH 9 and pressure of 1000 kPa. Copyright © 2003 Society of Chemical Industry 相似文献
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With the growing demand in e-learning system, traditional e-learning systems have dramatically evolved to provide more adaptive ways of learning, in terms of learning objectives, courses, individual learning processes, and so on. This paper reports on differences in learning experience from the learner’s perspectives when using an adaptive e-learning system, where the learner’s knowledge or skill level is used to configure the learning path. Central to this study is the evaluation of a dynamic content sequencing system (DCSS), with empirical outcomes being interpreted using Csikszentmihalyi’s flow theory (i.e., Flow, Boredom, and Anxiety). A total of 80 participants carried out a one-way between-subject study controlled by the type of e-learning system (i.e., the DCSS vs. the non-DCSS). The results indicated that the lower or medium achievers gained certain benefits from the DCSS, whilst the high achievers in learning performance might suffer from boredom when using the DCSS. These contrasting findings can be suggested as a pragmatic design guideline for developing more engaging computer-based learning systems for unsupervised learning situations. 相似文献
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