title: Chemical modification of Dendrocalamus asper bamboo with citric acid and boron compounds: Effects on the physical-chemical, mechanical and thermal properties

authors: Gauss, Christian

abstract: The effect of environmentally friendly treatment using citric acid and boron compounds on the physical-chemical and mechanical properties and thermal degradation of D. asper bamboo was investigated. The chemical modification using citric acid reduced the moisture uptake of bamboo by 32%, the water absorption by 26%, and thickness and width swelling by 43% and 31%, respectively, in comparison with the reference. FTIR analysis revealed the effect of the esterification process with an increase of the carbonyl/hydroxyl absorbance ratio, which explains the reductions in water absorption and swelling. No significant change was identified on the cellulose crystallinity determined by XRD, with only a small increase of the boron-treated samples. TG/DSC measurements showed that boron compounds cause a reduction of weight loss and decrease the exothermic heat flow upon heating under synthetic air flow. However, the modification with citric acid caused slightly higher thermal degradation in the same conditions of testing, which was overcome by the addition of boron compounds in the treatment solution. Enhanced mechanical performance was observed on bamboo samples treated only with boron compounds, while samples chemically modified by citric acid presented no changes or a small increase in compression and bending properties. Nevertheless, fibre detachment and structural changes on hemicellulose/cellulose caused a small decrease in shear strength and a considerable decrease, about 30%, in tensile strength. The overall results provided an insightful understanding regarding the chemical modification of bamboo, revealing new possibilities of treatment for the improvements of dimensional and thermal stability without the use of hazardous chemicals.

text: Chemical modification of Dendrocalamus asper bamboo with citric acid and boron compounds: Effects on the physical-chemical, mechanical and thermal properties The effect of environmentally friendly treatment using citric acid and boron compounds on the physical-chemical and mechanical properties and thermal degradation of D. asper bamboo was investigated. The chemical modification using citric acid reduced the moisture uptake of bamboo by 32%, the water absorption by 26%, and thickness and width swelling by 43% and 31%, respectively, in comparison with the reference. FTIR analysis revealed the effect of the esterification process with an increase of the carbonyl/hydroxyl absorbance ratio, which explains the reductions in water absorption and swelling. No significant change was identified on the cellulose crystallinity determined by XRD, with only a small increase of the boron-treated samples. TG/DSC measurements showed that boron compounds cause a reduction of weight loss and decrease the exothermic heat flow upon heating under synthetic air flow. However, the modification with citric acid caused slightly higher thermal degradation in the same conditions of testing, which was overcome by the addition of boron compounds in the treatment solution. Enhanced mechanical performance was observed on bamboo samples treated only with boron compounds, while samples chemically modified by citric acid presented no changes or a small increase in compression and bending properties. Nevertheless, fibre detachment and structural changes on hemicellulose/cellulose caused a small decrease in shear strength and a considerable decrease, about 30%, in tensile strength. The overall results provided an insightful understanding regarding the chemical modification of bamboo, revealing new possibilities of treatment for the improvements of dimensional and thermal stability without the use of hazardous chemicals.

year: 2021

title: AusTraits, a curated plant trait database for the Australian flora

authors: Falster, D.

subjects: Science & Technology

abstract: We introduce the AusTraits database - a compilation of values of plant traits for taxa in the Australian flora (hereafter AusTraits). AusTraits synthesises data on 448 traits across 28,640 taxa from field campaigns, published literature, taxonomic monographs, and individual taxon descriptions. Traits vary in scope from physiological measures of performance (e.g. photosynthetic gas exchange, water-use efficiency) to morphological attributes (e.g. leaf area, seed mass, plant height) which link to aspects of ecological variation. AusTraits contains curated and harmonised individual- and species-level measurements coupled to, where available, contextual information on site properties and experimental conditions. This article provides information on version 3.0.2 of AusTraits which contains data for 997,808 trait-by-taxon combinations. We envision AusTraits as an ongoing collaborative initiative for easily archiving and sharing trait data, which also provides a template for other national or regional initiatives globally to fill persistent gaps in trait knowledge.

text: AusTraits, a curated plant trait database for the Australian flora We introduce the AusTraits database - a compilation of values of plant traits for taxa in the Australian flora (hereafter AusTraits). AusTraits synthesises data on 448 traits across 28,640 taxa from field campaigns, published literature, taxonomic monographs, and individual taxon descriptions. Traits vary in scope from physiological measures of performance (e.g. photosynthetic gas exchange, water-use efficiency) to morphological attributes (e.g. leaf area, seed mass, plant height) which link to aspects of ecological variation. AusTraits contains curated and harmonised individual- and species-level measurements coupled to, where available, contextual information on site properties and experimental conditions. This article provides information on version 3.0.2 of AusTraits which contains data for 997,808 trait-by-taxon combinations. We envision AusTraits as an ongoing collaborative initiative for easily archiving and sharing trait data, which also provides a template for other national or regional initiatives globally to fill persistent gaps in trait knowledge.

year: 2021

title: Rights to water an indigenous right?

authors: Toki, Valmaine

abstract: The United Nations Declaration on the Rights of Indigenous People ("the Declaration") was adopted by the United Nations General Assembly in September 2007 with a majority of 143 states in favour.  Since then Australia, New Zealand, Canada and the United States have also signalled their support for the Declaration.

text: Rights to water an indigenous right? The United Nations Declaration on the Rights of Indigenous People ("the Declaration") was adopted by the United Nations General Assembly in September 2007 with a majority of 143 states in favour.  Since then Australia, New Zealand, Canada and the United States have also signalled their support for the Declaration.

year: 2012