Sujittra Singta, Amnat Chidthaisong*, Daisuke Komori, Vanisa Surapioith and Wonsik Kim
Abstract: This study reports the estimate of evapotranspiration (ET) over a rainfed sugarcane field in Takfa, Nakornsawan province during May 2011 to Feb 2014. The ET was measured by eddy covariance method. The annual ET ranged from 685 to 800 mm year-1. The total ET was 851.17 mm for plant cane while it was 655.20 mm for first ratoon cane. In both plant cane and ratoon cane, total ET in germination phase was less than other growth phases, mainly due to less precipitation and low plant growth activity. The daily ET varied from 1 mm day-1 in the dry season to 7 mm day-1 in the wet season. Net radiation and soil moisture were found to be the main drivers of variations in ET. Water use efficiency (WUE) of plant cane was less than of the ratoon cane due to higher ET and precipitation in plant cane.
Keywords: Evapotranspiration, Eddy covariance, Sugarcane plantation, Water use efficiency.
Nutsanun Klueb-arb, Surawut Chuangchote*, Kamonchanok Roongraung, Navadol Laosiripojana and Takashi Sagawa
Abstract: Heterogeneous TiO2 photocatalysis is widely used in various ways in environmental and energy fields, including water and air purifications, self-cleaning surfaces, photocatalytic reaction, and hydrogen production.In this work, silver (Ag), copper (Cu), and rubidium (Rb) at various contents (1 wt%, 3 wt%, and 5 wt. %) were used as metals for doping on commercial TiO2 nanoparticles by impregnation technique. All samples were calcined under air (400°C for 3 h).The structural characteristics and optical property of metal-doped TiO2 nanoparticles were characterized by field emission scanning electron microscopy (FESEM), UV-visible (UV-vis) spectroscopy, and photoluminescence (PL) spectroscopy. From FESEM, it was found that pristine TiO2 showed low agglomeration, while metal-doped TiO2 at high metal content showed more agglomeration.From UV-vis reflection spectra, it was found that increase in content of metal in TiO2 nanoparticles resulted in lower reflectance. These results are in line with PL spectra. PL intensity reduced with increasing metal content. It was found that 5 wt. % Cu-doped TiO2 showed the lowest PL intensity, implied low electron-hole recombination rate (good property for enhancement of photocatalytic activity of the materials).It can be concluded that metal-doped TiO2 nanoparticles are promising materials to be utilized as photocatalysts for various energy and environmental applications.
Keywords: metal doping, TiO2, light absorption, photoluminescence.
Panuruj Asawaworarit, Pornlada Daorattanachai and Navadol Laosiripojana*
Abstract: In this work, the depolymerization of organosolv lignin obtained from our own fractionation process from bagasse was studied.The effects of operating conditions including temperature (250-350°C) and time (1-5 h) in the presence of methyl isobutyl ketone (MIBK) were investigated. Moreover, bimetallic NiMo and trimetallic NiMoRe sulfides supported on g-Al2O3 were also tested for comparison. Experiments revealed that at 350°C for 5 h, sulfided NiMoRe catalyst provided the highest phenolic product yield of 33.3%. The main phenolic monomers obtained are guaiacol and 4-ethylphenol. The result in this work suggested that NiMoRe sulfide catalyst is one of the alternative choices for catalytic depolymerization reaction in order to convert lignin to high value-added chemicals.
Keywords: Lignin depolymerization; Organosolv bagasse lignin; NiMoRe sulfide.
Robert H.B. Exell