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121.
Syazwan Afif Mohd Zobir Zulkarnain Zainal Mohd Zobir Hussein 《Materials Chemistry and Physics》2010,124(1):477-481
The effect of the addition of very small amount of polyvinyl alcohol (PVA) on the resulting physicochemical properties of ZnO synthesized by ethylene glycol-hydrothermal method was studied. Significant change in particle size distribution and specific surface area can be observed even only 0.02% PVA (w/w) was added into the ethylene glycol (EG) solution, in which the median particle size distribution increased from 5 to 8 nm and at the same time the specific surface area is also increased to nearly 50%. Further addition of PVA resulted in the decrease of the specific surface area due to the formation of agglomeration and aggregation of particles as observed by FESEM study. This study shows that the presence of minute amount of polymer, PVA plays very crucial role in determining the resulting properties of the synthesized ZnO by EG-hydrothermal method. 相似文献
122.
DOE applied to multi-response optimisation study on performance,combustion and emission characteristics of a VCR diesel engine 总被引:1,自引:0,他引:1
Syed Azam Pasha Quadri M. Masood Tabish Wahidi Mohd Ghouse Sundkey Mohd Wajid 《国际自然能源杂志》2017,38(8):759-764
There are various parameters which may influence the IC engine performance. The trial and error method is a technique used to identify the best parameters. However, this method demands extensive experimental work and results in a great waste of time and resources. Thus, the design of experiments (DOEs) developed by Taguchi is employed. The multi-responses which need to be maximised are brake thermal efficiency, mechanical efficiency, cylinder pressure and cumulative heat release rate, whereas the responses which are to be minimised are specific fuel consumption, oxides of nitrogen and carbon monoxide. In the present study, an optimised DOE(L9) orthogonal array based on the Taguchi statistical method was formulated and a series of experiments were conducted under controlled supervision by considering three different injection operating pressures (IOPs) (200, 220 and 240 bar) and three different compression ratios (CRs) (16.5, 17.5 and 18.5). The main objective of this paper is to find the best suited IOP and CR values which obtain higher performance, better combustion and lower emissions. 相似文献
123.
Masoud Zabeti Wan Mohd Ashri Wan Daud Mohamed Kheireddine Aroua 《Applied Catalysis A: General》2009,366(1):154-159
In this work the response surface methodology (RSM) in conjunction with the central composite design (CCD) were used to optimize the activity of CaO/Al2O3 solid catalysts for the production of biodiesel. In order to measure the catalyst activity, we used palm oil as a representative raw material for the conversion to biodiesel. The biodiesel production was carried out in a batch laboratory scale reactor. The results showed that both the calcination temperature and the amount of calcium oxide loaded on the support had significant positive effects on the biodiesel yield. The maximum basicity and biodiesel yield obtained were about 194 μmol/g and 94%, respectively. Overall, the catalyst showed high performance at moderate operating conditions and its activity was maintained after two cycles. 相似文献
124.
L. B. Abdulqadir N. F. Mohd Nor R. Lewis T. Slatter 《Tribology - Materials, Surfaces & Interfaces》2018,12(3):115-129
Confronted with the contemporary challenges of maximising energy efficiency with minimal impact on the environment, the automotive industry has developed various technologies to tackle them. Most of these technologies, however, have wider implications on the tribological performance of the automotive engines due to resultant soot build-up. This paper reviews the effects that attempts by stakeholders to satisfy requirements for reduced fuel consumption, reduced emissions and extended service intervals have had on increasing soot levels to an extent that can lead to engine component failure. Three areas have been identified that have either not been explored or not widely explored in the study of automotive soot namely: numerical simulation and modelling of soot wear, soot effects on wear of actual engine components and the wear and friction performance of non-metallic materials used in internal combustion engines. A paper-grading system is also utilised to present an overview of how sooty oil-related research covers various areas. 相似文献
125.
Elyas Sadeq Alaghbari Zulkarnain Zainal Imad Hamadneh Mohd Zobir Bin Hussein Mohd Haniff Bin Wahid 《Journal of Superconductivity and Novel Magnetism》2012,25(2):255-260
Zn- and Ca-doped ErBa2Cu3O7−δ
were successfully prepared via coprecipitation method using metal acetates as the starting salts. The precipitated samples
were calcined for 20 h at 900 °C and sintered at 920 °C for 24 h. All heat treatments were carried out under oxygen environment.
Results show that there is a selectivity of the doping site depending on the ionic radius of the dopant. Furthermore, increase
in the critical temperature, T
c
, was observed in 0.05 mole of calcium and zinc doped samples. The difference in ionic radius of the dopant led to the increase
in porosity as the ionic radius decreases. On the other hand, structural distortion increased as the difference of ionic radius
became larger. 相似文献
126.
Nor Azah Yusof Nor Dyana Zakaria Nor Amirah Mohd Maamor Abdul Halim Abdullah Md. Jelas Haron 《International journal of molecular sciences》2013,14(2):3993-4004
Molecularly imprinted polymers (MIPs) were prepared by bulk polymerization in acetonitrile using 2,4-dinitrophenol, acrylamide, ethylene glycol dimethacrylate, and benzoyl peroxide, as the template, functional monomer, cross-linker, and initiator, respectively. The MIP membrane was prepared by hybridization of MIP particles with cellulose acetate (CA) and polystyrene (PS) after being ground and sieved. The prepared MIP membrane was characterized using Fourier transform infrared spectroscopy and scanning electron microscopy. The parameters studied for the removal of 2,4-dinitrophenol included the effect of pH, sorption kinetics, and the selectivity of the MIP membrane. Maximum sorption of 2,4-nitrophenol by the fabricated CA membrane with MIP (CA-MIP) and the PS membrane with MIP (PS-MIP) was observed at pH 7.0 and pH 5.0, respectively. The sorption of 2,4-dinitrophenol by CA-MIP and PS-MIP followed a pseudo–second-order kinetic model. For a selectivity study, 2,4-dichlorophenol, 3-chlorophenol, and phenol were selected as potential interferences. The sorption capability of CA-MIP and PS-MIP towards 2,4-dinitrophenol was observed to be higher than that of 2,4-dichlorophenol, 3-chlorophenol, or phenol. 相似文献
127.
Conductive fibers based on polyaniline (PANI) and polyacrylonitrile (PAN) were obtained by stirring with magnetic bar. This research was conducted to investigate conducting fibers of polyaniline:polyacrylonitrile (PANI:PAN) composite with different weight ratios of aniline in PAN matrix. The fibers were prepared by stirring process. The best conductivity behavior of the fibers was obtained with 5 mL of aniline. The fibers obtained were characterized using Fourier-transform infrared spectra (FTIR), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). The variation of electrical conductivity with different type doping agents (HCl, H2SO4 and HClO4) and the stability in terms of DC electrical conductivity retention was studied in an oxidative environment by isothermal characteristics. 相似文献
128.
Hammed Ademola Monsur Hamzah Mohd Salleh Hassan A. Alkahtani 《International Journal of Food Properties》2013,16(6):1224-1236
Fish gelatins obtained from perch fish skin pretreated with various solutions containing acetic acid, sodium hydroxide (NaOH) and sodium chloride (NaCl) were successfully characterized for their nanostructure pattern using field emission scanning electron microscopy. Each pretreatment transformed collagen to gelatin with fibril, zigzag cracks, straight rods, and cross-linked rods nanostructure patterns. Pretreatment solutions also affect the gel yield, gel strength, amino acid profile, and functional groups in perch gelatin as analyzed by Fourier transform infrared spectroscopy. Samples pretreated with NaCl, NaOH, and acetic acid solution showed the highest gel yield (22.84%) and gel strength (179.84 g). Fourier transform infrared spectra for perch gelatins also revealed weak C–N amide II and III bond stretches as well as weak C=O bond stretch. 相似文献
129.
130.
Li Wan Yoon Gek Cheng Ngoh Adeline Seak May Chua Mohd. Ali Hashim 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2011,86(10):1342-1348
BACKGROUND: Much attention has been given to applying ionic liquids (ILs) as an alternative pretreatment method for lignocellulosic biomass. This study aims to select the most suitable type of IL for pretreating sugarcane bagasse (SCB). The potential of ILs for pretreatment was evaluated and compared with conventional pretreatment media, acids and alkalis. The performance of the pretreatment media was evaluated based on the amount of reducing sugar produced from enzymatic saccharification, the energy requirement, and changes in the chemical structure and crystallinity index of the pretreated bagasse. RESULTS: 1‐ethyl‐3‐methylimidazolium acetate [EMIM]oAc was selected as the most suitable IL for SCB pretreatment. The optimum yields of reducing sugar obtained from [EMIM]oAc‐, alkali‐, and acid‐pretreated SCB were 69.5%, 92.8% and 41.3%, respectively. Although a lower yield of reducing sugar was obtained, [EMIM]oAc pretreatment required the least energy to pretreat 1 kg of SCB. Moreover, the percentage of SCB loss during [EMIM]oAc pretreatment was the lowest. [EMIM]oAc‐pretreated SCB also had the lowest crystallinity index (CI) with the most amorphous structure. CONCLUSION: [EMIM]oAc appears to be another option for pretreating SCB, and other issues such as the recyclability of [EMIM]oAc is worth investigating. Copyright © 2011 Society of Chemical Industry 相似文献