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Infrared spectroscopy coupled with partial least squares (PLS) regression has been shown to be a rapid alternative to wet chemical analytical methods for determining the cell-wall compositions of wood. Both near infrared (NIR) spectroscopy, and mid-infrared spectroscopy with attenuated total reflectance Fourier transform infrared (ATR FTIR) sampling, coupled with PLS regression, can be used to quickly and accurately predict the lignin contents and monosaccharide compositions of milled wood. However, milling wood can be time consuming and laborious. In this study we demonstrate that PLS-1 models built using NIR and ATR FTIR spectra of milled Pinus radiata wood, with different sized wood particles and different moisture contents, can rapidly and accurately predict the cell-wall compositions of solid wood. A robust assessment of the prediction accuracy was conducted using a separate test set of solid wood samples with both ‘smooth’ and ‘rough’ surface finishes. The lowest standard error (SE) values for most of the compositional predictions were obtained for the ‘rough’ solid wood samples, using PLS-1 models built from NIR spectra of ‘large’ milled wood particles (0.422 mm) with ambient moisture content. The SE achieved for NIR spectroscopy prediction of lignin for the ‘rough’ solid wood was 1.91%, and for the monosaccharides, arabinose (0.37%), xylose (1.25%), galactose (2.00%), mannose (1.54%), and 4-O-methyl glucuronic acid (0.24%). The powerful combination of NIR spectroscopy with PLS regression offers an attractive method for rapid prediction of cell-wall compositions of solid wood samples, thus avoiding milling. In addition, this technique highlights the different levels of these cell-wall components in opposite and compressed regions in solid wood.

Because plant cell walls vary in their polysaccharide compositions and lignin contents, their monosaccharide compositions and lignin contents are often determined, but these analyses are time consuming and laborious. We therefore investigated Fourier transform infrared (FTIR) spectroscopy coupled with partial least squares (PLS) regression analysis as a way of rapidly predicting the monosaccharide compositions and lignin contents of the cell walls of compression wood (CW) and opposite wood (OW) of the gymnosperm Pinus radiata. The effects were investigated of sample moisture content (ambient or dry) and sample particle size (large particles

Graphene has received significant attention in recent years due to its outstanding electronic, mechanical, chemical and physical properties. Graphene materials can potentially be used in a variety of applications, such as functional nanocomposites, electrodes, flexible transparent devices and thin conductive films. This article focuses on the analysis of structural evolution and development of different of reduced graphene oxides (rGOs), and the results are compared with structural features of functionalised reduced graphene oxide and graphene. The aromatic disorder and irregularity of these materials influence their own properties; particularly, their electrical conductivity aspects were studied indirectly through Raman spectroscopy. The quantification of their Raman spectra and microstructural analysis were examined to assess the relationship between aromatic structures and electrical conduction mechanism. The results showed that aromaticity of GO changes under different chemical reduction treatments and hydroiodic acid reduction gave an electrical conductivity of 103.3 S cm−1 as highest amongst a number of rGOs produced. Moreover, the integrity of aromatic structure through different reduced graphene oxides changed quite significantly and the Raman results were able to correlate the electrical conductivity with their structural regularity.

Rapid, simple microchannel prototyping is critical for the development of modern microfluidic devices and platforms. Laser cutting (ablation) using a commercially available continuous wave (CW) CO2 laser followed by thermal bonding is one of the most common approaches for prototyping in thermoplastics such as polymethyl methacrylate (PMMA). However, this technique suffers from poorly controlled channel quality, inconsistent results from solvent-based post-processing, and inconsistency of thermal bonding. We have overcome these challenges through a systematic study of channel ablation in PMMA using a CW CO2 laser. A new solvent treatment approach results in clearly improved microchannel quality and processing consistency, with negligible residual solvent. Thermal bonding of the processed material showed fourfold increase in bonding strength with full retention of PMMA’s favourable optical clarity. As proof of concept, a high-quality three-layered microfluidic prototype is fabricated with this new method and its performance demonstrated.

Agriculture, Domestic Production, and Site Function: Microfossil Analyses and Late Prehistoric Landscapes of the Society Islands. Pollen, phytolith, and starch analyses of sediment samples from the ‘Opunohu Valley, Mo‘orea, Society Islands were completed to retrieve data on prehistoric vegetation, Ma‘ohi planting practices, and cultigens. A second goal was to test whether microfossil data can aid in the identification of food production, storage, and plant processing locales at the local and community level, as modeled from ethnographic and ethnohistoric literature. In addition, we use Fourier Transform InfraRed spectroscopy (FTIR) on degraded and suspected starch, to provide another line of evidence for identifying starch grains. The ‘Opunohu Valley microfossil analyses provide direct evidence for 1) past environments and vegetation, including human–induced environmental change and pre–contact agricultural practices, as well as tentative evidence for 2) cultivation and plant processing, 3) domestic production and consumption, including cooking practices and surplus food storage, and 4) site function and specialization that are referenced in the ethnohistoric literature. Twenty economic taxa were identified in addition to grasses, sedges, and palms. Banana leaf phyotliths found in sub–surface pits in residential contexts provide supporting evidence that such features served for short–term food storage or breadfruit fermentation. In addition, we model the potential economic uses of Pandanus, Casuarina, Weinmannia, and paper mulberry based on microfossil data and ethnohistoric accounts. While microfossil studies are of clear interest for reconstructing landscapes, human–environmental interactions, and agricultural practices, they also have relevance to questions concerning socio–economic transformations at the local and community levels.

Previous wetland vegetation records from Easter Island showing deforestation and Polynesian agriculture are limited to cores that rely on pollen, with a single cultigen pollen type identified: Urticaceae/Moraceae, possibly Broussonetia payrifera (paper mulberry). Here we redress this by also using phytolith and starch analyses on four lake sediment cores on a ~350-m transect along the southwest edge of Rano Kau, focusing on in-washed basal clayey layers. We also use a new method, Fourier transform infrared spectroscopy, to positively identify degraded starch collected from sedimentary deposits. The cores are the first samples recovered from an area in the lake that (a) lies below the relict village of Orongo, (b) is near a section of the crater believed to be most accessible from the Pacific coast, and (c) is far from the northern crater rim and receives high solar radiation, a likely benefit for crops of tropical origin. Pollen and phytoliths are abundant in the clayey layers and sparse in overlying layers of organic lake detritus and living rhizomes. Mixing of core deposits as a result of human activity has disordered the radiocarbon sequence, precluding development of an reliable chronology. Containing microfossils of several introduced cultigens, the clayey layers represent gardened terraces that have slumped into the lake. The data indicate large-scale deforestation and a mixed-crop production system including Broussonetia papyrifera, Colocasia esculenta (taro), Dioscorea alata (greater yam), Ipomoea batatas (sweet potato), Lagenaria siceraria (bottle gourd) and Musa (banana) sp. The data show (a) the potential for using the combined analyses to provide direct evidence of Polynesian horticulture on Easter Island and (b) that the island’s wetlands potentially hold extensive horticultural records. The study highlights the concept of ‘transported landscapes,’ whereby colonising people replace indigenous forests with artificial, imported agricultural landscapes.