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Search Results: 1 - 10 of 6119 matches for " Astimar Abdul Aziz "
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Effect of Refining Parameters on Medium Density Fibreboard (MDF) Properties from Oil Palm Trunk  [PDF]
Zawawi Ibrahim, Astimar Abdul Aziz, Ridzuan Ramli, Anis Mokhtar, SiJoon Lee
Open Journal of Composite Materials (OJCM) , 2013, DOI: 10.4236/ojcm.2013.34013
Abstract: The properties of medium density fibreboard (MDF) made from oil palm trunk (OPT) as affected by refining pressure and preheating time were investigated. The OPT chips were refined in the MDF pilot plant by using four refining pressures (2, 4, 6 and 8 bar) and four different preheating time (100, 200, 300 and 400 seconds). The refined fibres were blended with 10% of urea formaldehyde with a board target density of 720 kg/m3. MDF boards were evaluated based on European Standard EN 622-5:2006 for thickness swelling (TS), internal bonding (IB), modulus of rupture (MOR) and modulus of elasticity (MOE). Analysis of variance (ANOVA) was used to analyze the significance of the factors. The results from this study indicated that refining pressure and preheating time are significant factors for all MDF properties. Low refining pressure and preheating time produced higher TS, lower MOR and MOE with poor bonding than those boards prepared from fibres refined at higher refining pressure and longer preheating time. OPT fibre treated with 8 bar produced good swelling resistance but detrimental on mechanical properties of the finish board. 6 bar steam pressure offered the highest value of mechanical properties (MOE, MOR and IB). Boards from intermediate refining condition (6 bar and 300 seconds) were found the better board properties having 14.58%, 0.73 N/mm2, 38 N/mm2 and 3597 N/mm2 for TS, IB, MOR and MOE respectively.
Development of Cu Nanoparticle Loaded Oil Palm Fibre Reinforced Nanocomposite  [PDF]
Ridzuan Ramli, Maksudur Rahman Khan, Najmul Kabir Chowdhury, Mohammad Dalour Hossen Beg, Rohaya Mohamed Halim, Astimar Abdul Aziz, Zawawi Ibrahim, Nahrul Hayawin Zainal
Advances in Nanoparticles (ANP) , 2013, DOI: 10.4236/anp.2013.24049
Abstract:

Functionalized copper nanoparticles (FCuNPs) have been synthesized by chemical reduction method and polyvinyl alcohol (PVA) performed as a stabilizer in that medium. Analysis observed that the average size of the synthesized FCuNPs was 3.5 nm. The obtained FCuNPs were loaded in the oil palm empty fruit bunch (EFB) natural fibre. Before the loading of FCuNPs in EFB fibres, the surface of the fibres is tailored by the cationic agent CHPTAC since they have a natural tendency to exhibit negatively charged surface owing to the presence of large amount of hydroxyl groups. Thereafter, different types of composite were developed and their properties were studied. The composites were developed by using the untreated empty fruit bunch (UEFB) fibres and FCuNPs loaded EFB (NP-CAEFB) fibres with commercially available unsaturated polyester resin (UPER). The synthesized composites were characterized through FTIR, FESEM, XRD, DSC, tensile strength tests, etc. The obtained biodegradation results indicated that significant weight loss was not observed for neat PER and PER/FNP-CAEFB nanocomposite, whereas, the UEFB/VUPER composite showed ca. 21.4% weight loss at 90 days, which was considered rationally due to the preferential degradation of the fibre.

In-Situ Impregnation of Copper Nanoparticles on Palm Empty Fruit Bunch Powder  [PDF]
Ridzuan Ramli, Md. Maksudur Rahman Khan, Rosli Mohd Yunus, Huei Ruey Ong, Rohaya Mohamed Halim, Astimar Abdul Aziz, Zawawi Ibrahim, Nahrul Hayawin Zainal
Advances in Nanoparticles (ANP) , 2014, DOI: 10.4236/anp.2014.33009
Abstract:
Copper nanoparticles were impregnated onto oil palm empty fruit bunch (EFB) powders via in-situ sol-gel method. The impregnation and interfacial interaction of copper nanoparticles with EFB were analysed by fourier transformed infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX) and atomic force microscopy (AFM). The interaction of copper nanoparticles with the surface functional groups of EFB powders was identified by FTIR analysis. The peak shift of O-H and C-O functional groups indicated the interaction between EFB and copper nanoparticles. Besides that, XRD and EDX analysis confirmed the formation of copper nanoparticles on EFB powder. Due to the copper impregnation, the crystallinity of the EFB was increased as shown by XRD. The particles size of nanoparticles was analysed via TEM and AFM where the sizes were in the range of 60 - 100 nm. These findings strongly suggest that, copper nanoparticles impregnated EFB powders can be synthesized via in- situ sol gel method.
Dimensional Stability Properties of Medium Density Fibreboard (MDF) from Treated Oil Palm (Elaeis guineensis) Empty Fruit Bunches (EFB) Fibres  [PDF]
Zawawi Ibrahim, Mansur Ahmad, Astimar Abdul Aziz, Ridzuan Ramli, Mohd Ariff Jamaludin, Suhaimi Muhammed, Aisyah Humaira Alias
Open Journal of Composite Materials (OJCM) , 2016, DOI: 10.4236/ojcm.2016.64009
Abstract: The aim of the study was to investigate the effect of pre-treatments by using sodium hydroxide (NaOH) and acetic acid on oil palm Empty Fruit Bunch (EFB) fibres for the production of Medium Density Fibreboard (MDF). The EFB fibres were treated with chemicals in the concentration range of 0.2%, 0.4%, 0.6% and 0.8% prior to refining. Single-homogenous layer MDF with 12 mm thickness and density of 720 kg/m3 was produced. Urea-Formaldehyde (UF) was applied at 10% loading (based on dry weight of dry fibres) as a binder. The physical properties (Water Absorption (WA) and Thickness Swelling (TS)) of the produced panels were tested according to European Standard, EN 622-5:2006. The results show that types of chemical used had greater effects than concentration on the dimensional stability of the MDF. EFB fibres treated with acetic acid produced MDF with better dimensional stability compared to the MDF NaOH treated fibres. High concentration of NaOH produced poor dimensional stability in the panels.
Lp Inequalities for Polynomials  [PDF]
Abdul Aziz, Nisar A. Rather
Applied Mathematics (AM) , 2011, DOI: 10.4236/am.2011.23038
Abstract: In this paper we consider a problem of investigating the dependence of on for every real or complex number with , , and present certain compact generali- zations which, besides yielding some interesting results as corollaries, include some well-known results, in particular, those of Zygmund, Bernstein, De-Bruijn, Erdös-Lax and Boas and Rahman as special cases.
Comparative Evaluation of the Anti-ulcer Activity of Curcumin and Omeprazole during the Acute Phase of Gastric Ulcer—Efficacy of Curcumin in Gastric Ulcer Prevention against Omeprazole  [PDF]
Karolin Kamel Abdul-Aziz
Food and Nutrition Sciences (FNS) , 2011, DOI: 10.4236/fns.2011.26088
Abstract: We have confirmed in our laboratory the antiulcer activity of curcumin during the acute chronic phase of gastric ulcer disease at doses of 20, 40 and 80 mg/kg (dissolved in saline solution). In the previous study, the potent effective dose of curcumin was 80 mg/kg that appears a propitious protective effect against gastric ulcer development. Therefore, the comparison between such recommended dose of curcumin and one of the proton pump inhibitors (PPIs) staff is worth-while. Since, the pharmacological control of gastric acid secretion is the main desired goal for gastro-cytoprotection, particularly, the H+/K+-ATPase (acid proton pump) inhibitors. Nevertheless, several studies have indicated that long-term inhibition of gastric acid secretion results in mucosal hyperplasia and carcinoid tumor development, due to increase circulating gastrin levels. Ulcer and the preventive indexes were scored, mucin, juice volume, total acidity, luminal haemoglobin, total antioxidant and total peroxide were evaluated. The pro-inflammatory cytokine IL-6 and the major angiogenic growth factor VEGF levels were measured. Conclusion, curcumin and omeprazole are potentially preventing gastric lesions development in the gastric wall during the acute phase of gastric ulcer diseases, but curcumin was more potent in its effect. Curcumin promotes gastric ulcer prevention/healing by induction of angiogenesis in the granular tissue of ulcers. That may be via upregulation of VEGF expression as reflected from VEGF level in serum and gastric juice, however, omeprazole might be has no role in this story.
Bounds for the Zeros of a Polynomial with Restricted Coefficients  [PDF]
Abdul Aziz, Bashir Ahmad Zargar
Applied Mathematics (AM) , 2012, DOI: 10.4236/am.2012.31005
Abstract: In this paper we shall obtain some interesting extensions and generalizations of a well-known theorem due to Enestrom and Kakeya according to which all the zeros of a polynomial P(Z =αnZn+...+α1Z+α0satisfying the restriction αn≥αn-1≥...≥α1≥α0≥0 lie in the closed unit disk.
Entropy Generation in Pressure Gradient Assisted Couette Flow with Different Thermal Boundary Conditions
Abdul Aziz
Entropy , 2006, DOI: 10.3390/e8020050
Abstract: The present paper is concerned with an analytical study of entropy generation in viscous, incompressible Couette flow between a stationary plate and a moving plate. The flow induced by the moving plate is assisted by a constant pressure gradient along the flow direction. Four different combinations of thermal boundary conditions are investigated: (a) plates at different temperatures, (b) stationary plate at a fixed temperature and moving plate subjected to a constant heat flux, (c) stationary plate at a fixed temperature and convection at the moving plate, and (d) convection at both plates. Besides the velocity and temperature profiles, dimensionless results are presented for the entropy generated due to heat transfer, the entropy generated due to viscous dissipation, and the total entropy generation. These results illustrate the effect of pressure gradient, temperature asymmetry, heat flux, convection Biot numbers, and ambient temperatures. For certain combinations of thermal variables, the total entropy generated is minimized.
Green Economy: Issues, Approach and Challenges in Muslim Countries  [PDF]
Negin Vaghefi, Chamhuri Siwar, Sarah Aziz Abdul Ghani Aziz
Theoretical Economics Letters (TEL) , 2015, DOI: 10.4236/tel.2015.51006
Abstract: Developing countries like most of Islamic countries need an economy that promotes growth and development, conserves natural capital, creates jobs, improves human well-being, and alleviates poverty and inequality. Such an economy is called green economy. Main problems that create a hard situation to implement green economy in most of Islamic countries are weak management, increasing poverty, many local and border conflicts, high economic dependency on natural re- sources, and increasing food insecurity. Governments as policy makers could introduce policies, regulations and incentives to promote green economy. This paper therefore attempts to discuss on how green economy can improve the livelihood security and poverty eradication in Islamic countries. It also seeks to understand which key intervention is needed to achieve a green economy in Muslim countries.
Forecasting on Crude Palm Oil Prices Using Artificial Intelligence Approaches  [PDF]
Abdul Aziz Karia, Imbarine Bujang, Ismail Ahmad
American Journal of Operations Research (AJOR) , 2013, DOI: 10.4236/ajor.2013.32023
Abstract:

An accurate prediction of crude palm oil (CPO) prices is important especially when investors deal with ever-increasing risks and uncertainties in the future. Therefore, the applicability of the forecasting approaches in predicting the CPO prices is becoming the matter into concerns. In this study, two artificial intelligence approaches, has been used namely artificial neural network (ANN) and adaptive neuro fuzzy inference system (ANFIS). We employed in-sample forecasting on daily free-on-board CPO prices in Malaysia and the series data stretching from a period of January first, 2004 to the end of December 2011. The predictability power of the artificial intelligence approaches was also made in regard with the statistical forecasting approach such as the autoregressive fractionally integrated moving average (ARFIMA) model. The general findings demonstrated that the ANN model is superior compared to the ANFIS and ARFIMA models in predicting the CPO prices.

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