Nanocrystalline cellulose(NCC) was produced from rice husk biomass(Oryza sativa) by a chemical extraction process to explore the potential aspect of agro-waste biomass in Australia. In this work, the delignified rice ...Nanocrystalline cellulose(NCC) was produced from rice husk biomass(Oryza sativa) by a chemical extraction process to explore the potential aspect of agro-waste biomass in Australia. In this work, the delignified rice husk pulp(D-RHP) was produced by alkaline delignification of raw rice husk biomass(R-RHB) using 4 mol·L^(-1) alkali solutions(Na OH) in a jacketed glass reactor under specific experimental conditions. D-RHP was bleached using 15% sodium hypochlorite, and the bleached rice husk pulp was coded as B-RHP. Finally,raw suspension of NCC was produced by the acid hydrolysis of B-RHP using 4 mol·L^(-1) sulphuric acid. The raw suspension of NCC was neutralized by a buffer solution and analyzed by TAPPI, FT-IR, XRD, SEM, AFM, and TEM. FT-IR spectra of NCC are different to R-RHB but similar with B-RHP and D-RHP. From XRD results, the crystallinity of NCC was found to be approximately 65%. In AFM analysis particle thicknesses have been confirmed to be in the range of(25 ± 15.14) nm or(27 ± 15.14) nm which is almost the same. From TEM analysis particle dimensions have been confirmed to be in the range of(50 ± 29.38) nm width and(550 ± 302.75) nm length with the aspect ratio ~ 11:1(length/diameter) at a 500 nm scale bar. On the other hand, at a 200 nm scale bar the particle dimensions have been confirmed to be in the range of(35 ± 17) nm width and(275 ± 151.38)nm length with the aspect ratio ~ 8:1. The aspect ratio of individual crystalline domain was determined in TEM analysis which is 10:1(100/10). Therefore the aspect ratios and dimensions of nanoparticles in NCC suspension are almost the same and in nano-meter scale, as confirmed from both AFM and TEM results. The yield of NCC from B-RHP was found to be approximately 95%, and the recovery of cellulose from R-RHB is about 90%.展开更多
We analyze morphometrics from a sample of 276 White-winged Black Tern(Chlidonias leucopterus) caught in north-west Australia on 4 March 2011. An estimated 40000 terns were present — the largest concentration of this ...We analyze morphometrics from a sample of 276 White-winged Black Tern(Chlidonias leucopterus) caught in north-west Australia on 4 March 2011. An estimated 40000 terns were present — the largest concentration of this species yet reported from Australia. When comparing juveniles with adults, only wing length and body mass differed significantly; however, juveniles were still easily recognized by plumage and wing molt as late as March. There was little evidence of any dramatic weight gain in adults before their northward migration. No morphological characteristic distinguishing sex was found. We confirmed that terns caught in this study did not appear to differ morphologically from those of the western palearctic populations. We describe wing molt based on data from 354 individuals captured and banded in Australia over 28 years. Wing molt proceeds in much the same way as found in other small terns.展开更多
基金funded by RMIT University, Melbourne, VIC 3001, Australia
文摘Nanocrystalline cellulose(NCC) was produced from rice husk biomass(Oryza sativa) by a chemical extraction process to explore the potential aspect of agro-waste biomass in Australia. In this work, the delignified rice husk pulp(D-RHP) was produced by alkaline delignification of raw rice husk biomass(R-RHB) using 4 mol·L^(-1) alkali solutions(Na OH) in a jacketed glass reactor under specific experimental conditions. D-RHP was bleached using 15% sodium hypochlorite, and the bleached rice husk pulp was coded as B-RHP. Finally,raw suspension of NCC was produced by the acid hydrolysis of B-RHP using 4 mol·L^(-1) sulphuric acid. The raw suspension of NCC was neutralized by a buffer solution and analyzed by TAPPI, FT-IR, XRD, SEM, AFM, and TEM. FT-IR spectra of NCC are different to R-RHB but similar with B-RHP and D-RHP. From XRD results, the crystallinity of NCC was found to be approximately 65%. In AFM analysis particle thicknesses have been confirmed to be in the range of(25 ± 15.14) nm or(27 ± 15.14) nm which is almost the same. From TEM analysis particle dimensions have been confirmed to be in the range of(50 ± 29.38) nm width and(550 ± 302.75) nm length with the aspect ratio ~ 11:1(length/diameter) at a 500 nm scale bar. On the other hand, at a 200 nm scale bar the particle dimensions have been confirmed to be in the range of(35 ± 17) nm width and(275 ± 151.38)nm length with the aspect ratio ~ 8:1. The aspect ratio of individual crystalline domain was determined in TEM analysis which is 10:1(100/10). Therefore the aspect ratios and dimensions of nanoparticles in NCC suspension are almost the same and in nano-meter scale, as confirmed from both AFM and TEM results. The yield of NCC from B-RHP was found to be approximately 95%, and the recovery of cellulose from R-RHB is about 90%.
文摘We analyze morphometrics from a sample of 276 White-winged Black Tern(Chlidonias leucopterus) caught in north-west Australia on 4 March 2011. An estimated 40000 terns were present — the largest concentration of this species yet reported from Australia. When comparing juveniles with adults, only wing length and body mass differed significantly; however, juveniles were still easily recognized by plumage and wing molt as late as March. There was little evidence of any dramatic weight gain in adults before their northward migration. No morphological characteristic distinguishing sex was found. We confirmed that terns caught in this study did not appear to differ morphologically from those of the western palearctic populations. We describe wing molt based on data from 354 individuals captured and banded in Australia over 28 years. Wing molt proceeds in much the same way as found in other small terns.
