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Yaacob M.H.,University Putra Malaysia | Yaacob M.H.,RMIT University | Ahmad M.Z.,RMIT University | Ahmad M.Z.,Mechanisation and Automation Research Center | And 5 more authors.
Sensors and Actuators, B: Chemical | Year: 2013

The gasochromic response of WO3 nanostructured films coated with a catalytic Pt or Pd layer on different transparent substrates upon exposure to H2 gas was investigated. WO3 nanostructured films with 500 nm thickness were coated with a 25 thick Pt or Pd layer. The films were prepared on quartz, glass, indium-doped tin oxide (ITO) and fluorine-doped tin oxide (FTO) conductive glass. The nanostructured WO3 was deposited by RF magnetron sputtering, and the Pt or Pd layer was deposited by DC sputtering. Characterization of the film revealed that the WO3 was deposited as nanoscale grains of varied size depending on the substrate. WO3 grains on quartz and glass were 30-40 nm in size. WO3 grain sizes on ITO and FTO were 40-60 nm and 300-500 nm, respectively. The WO3 films were observed to show strong gasochromic response, with absorbance changes measured in the Vis-NIR (500-1100 nm) range. The cumulative absorbance response towards H2 is the highest and more stable for Pd/WO3 films on quartz, glass and ITO, compared to the FTO substrate. The gasochromic effect was also stronger in Pd/WO3 films compared to Pt/WO3 films. © 2012 Elsevier B.V. All rights reserved. Source


Hanafi M.M.,University Putra Malaysia | Shahidullah S.M.,University Putra Malaysia | Niazuddin M.,University Putra Malaysia | Abd Aziz Z.,University Putra Malaysia | Mohammud C.H.,Mechanisation and Automation Research Center
Journal of Food, Agriculture and Environment | Year: 2010

The BRIS (Beach Ridges Interspersed with Swales) soils are the sandy marine deposits at the east coast of Peninsular Malaysia. The area is less suitable for usual field crops. Pineapple (Ananas comosus) may be introduced in the area for commercial cultivation. An experiment was conducted in the glass house condition of UPM. Pineapple plants were nurtured in the lysimeters, filled with BRIS 228177839soil, to assess the water requirements at different growth stages. Highest requirement of irrigation water was found 2.43 mm/day in initial stage (1). Subsequent development stage (2), midstage (3) and ripening stage (4) required smaller amount of irrigation water (approximately 1.55 mm/day). The daily average evapotranspiration (ETc) was 0.83 mm/day in Stage 1, followed by 0.73 mm/day in Stage 2. The lowest ETc was found 0.65 mm/day in Stage 3. The estimated crop coefficient (Kc) was found maximum 0.51 in initial stage. The Kc values showed a continuous decreasing trend up harvesting time. The second highest Kc value was 0.37 in development stage followed by 0.33 in mid-stage and minimum 0.30 during ripening stage. Source


Hanaf M.M.,University Putra Malaysia | Shahidullah S.M.,University Putra Malaysia | Niazuddin M.,University Putra Malaysia | Abd Aziz Z.,University Putra Malaysia | Mohammud C.H.,Mechanisation and Automation Research Center
International Journal of Agriculture and Biology | Year: 2010

An experiment was conducted to determine the response of four sea water treatments on an improved pineapple genotype "N-36" grown in Beach Ridges Interspersed with Swales (BRIS) soil. Sea water treatments were prepared by substitution of K with Na ions i.e., 0% (in control), 15%, 30% and 60% of required K doses were replaced by Na ions from sea water. Treatment effects were non-significant up to 30% sodium replacement from sea water. Na replacement (60%) showed significant impact on different growth parameters at different stages (8-10 months after planting). However, the fruit yield, the final target of crop harvest was not adversely affected at significance level. Therefore, sea water irrigation can easily fulfil 60% dose of potassium fertilizer by sodium ions for the production of pineapple in BRIS soil. © 2010 Friends Science Publishers. Source


Ou J.Z.,RMIT University | Ahmad M.Z.,RMIT University | Ahmad M.Z.,Mechanisation and Automation Research Center | Latham K.,RMIT University | And 3 more authors.
Procedia Engineering | Year: 2011

Nanosturctured WO 3 films were synthesized via anodization at elevated temperature. Nitric acid (HNO 3) and sulfuric acid (H 2SO 4) were employed for the first time. Different nanostructured morphologies were observed. The novel conductometric H 2 gas sensor has been developed based on these WO 3 films. The sensor with anodized WO 3 film in HNO 3 exhibited high sensitivity towards H 2 as low as 0.06% at relatively low operating temperature (120 °C). © 2011 Published by Elsevier Ltd. Source


Lee S.Y.,Mechanisation and Automation Research Center
Pertanika Journal of Science and Technology | Year: 2012

Tapioca starch, poly(lactic acid) and Cloisite 10A nanocomposite foams were prepared by twin screw extrusion. Residence time distribution (RTD) in an extruder is a useful means of determining optimal processing conditions for mixing, cooking and shearing reactions during the process. RTD was obtained by inputting a pulse-like stimulus and measuring its profile at the exit or other point in the extruder. During processing, after the steady state had been reached, a fixed amount of tracer was instantaneously fed into the extruder and its concentration was measured from the samples collected at fixed time intervals in the extruder exit. The tracer concentration was the value of the redness, a* was used as a measure of red colour intensity of the concentration of tracer in the extrudate. Meanwhile, the effects of two screw configurations (compression and mixing screws) and two barrel temperatures (150 and 160 oC) on RTD of nanocomposite foams were also studied. The influences of screw configurations and barrel temperatures on RTD were analyzed using the mean residence time (MRT) and variance. Screw configurations and temperatures had significant effects (P<0.05) on MTR. Mixing screws and lower temperature resulted in higher MRT and variance of RTD. © Universiti Putra Malaysia Press. Source

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