title: The Effect of Aqueous Urea on the Processing, Structure and Properties of CGM

authors: Pickering, Kim L.

subjects: corn gluten meal

abstract: Corn gluten meal (CGM) is potentially a cost-effective raw material for producing a bioderivable thermoplastic. However, CGM disintegrates to a powder subsequent to processing with polar plasticisers, such as water. The hypothesis of this study was that aqueous urea could be used to denature protein within CGM and therefore encourage protein–protein interactions leading to consolidated bioplastics when using water as a plasticiser. To assess this, the effects of aqueous urea on structure and properties of CGM with particular focus on storage were assessed. Processing of CGM with aqueous urea produced consolidated materials. FTIR analysis showed secondary structure was modified during processing, leading to increased amounts of α-helices and random coils and reduction of the amount of intermolecular β-sheets and turns. Above 6 wt% free water, the plasticising efficiency of water in processed CGM increased as the amount of denatured proteins increased. Below 6 wt% free water, protein secondary structure did not have a significant influence on thermal and flexural properties. It was found that storage environment and urea concentration influenced the rate of drying, however, the final water content was constant relative to CGM, and not urea. The materials were resistant to cracking at urea concentrations above 8 M, provided the mass loss during storage did not exceed 15 wt%.

text: The Effect of Aqueous Urea on the Processing, Structure and Properties of CGM Corn gluten meal (CGM) is potentially a cost-effective raw material for producing a bioderivable thermoplastic. However, CGM disintegrates to a powder subsequent to processing with polar plasticisers, such as water. The hypothesis of this study was that aqueous urea could be used to denature protein within CGM and therefore encourage protein–protein interactions leading to consolidated bioplastics when using water as a plasticiser. To assess this, the effects of aqueous urea on structure and properties of CGM with particular focus on storage were assessed. Processing of CGM with aqueous urea produced consolidated materials. FTIR analysis showed secondary structure was modified during processing, leading to increased amounts of α-helices and random coils and reduction of the amount of intermolecular β-sheets and turns. Above 6 wt% free water, the plasticising efficiency of water in processed CGM increased as the amount of denatured proteins increased. Below 6 wt% free water, protein secondary structure did not have a significant influence on thermal and flexural properties. It was found that storage environment and urea concentration influenced the rate of drying, however, the final water content was constant relative to CGM, and not urea. The materials were resistant to cracking at urea concentrations above 8 M, provided the mass loss during storage did not exceed 15 wt%.

year: 2012-06

title: Alum dosing effects on fish and aquatic invertebrates: Utuhina Stream 2021-2023

authors: Ling, Nicholas

abstract: To reduce external phosphorus loading to Lake Rotorua, the Bay of Plenty Regional Council has been granted resource consent to dose the Utuhina Stream with alum (aluminium sulphate). Aluminium binds phosphorus, preventing its uptake by phytoplankton and thereby inhibiting growth. Aluminium forms monomeric species outside of circum-neutral pH (pH 6-8), and these species can disrupt osmoregulation and respiration of aquatic organisms. The alum dose rate to the Utuhina Stream is dependent on discharge, with a maximum application rate of 1 ppm aluminium. This report presents the results of an on-going assessment of the fish and aquatic macroinvertebrate communities of the Utuhina Stream for 2021–2023.

text: Alum dosing effects on fish and aquatic invertebrates: Utuhina Stream 2021-2023 To reduce external phosphorus loading to Lake Rotorua, the Bay of Plenty Regional Council has been granted resource consent to dose the Utuhina Stream with alum (aluminium sulphate). Aluminium binds phosphorus, preventing its uptake by phytoplankton and thereby inhibiting growth. Aluminium forms monomeric species outside of circum-neutral pH (pH 6-8), and these species can disrupt osmoregulation and respiration of aquatic organisms. The alum dose rate to the Utuhina Stream is dependent on discharge, with a maximum application rate of 1 ppm aluminium. This report presents the results of an on-going assessment of the fish and aquatic macroinvertebrate communities of the Utuhina Stream for 2021–2023.

year: 2024

title: Voices of the land: Richard Nunns in conversation with Martin Lodge

authors: Nunns, Richard

abstract: Richard Nunns in conversation with Martin Lodge

text: Voices of the land: Richard Nunns in conversation with Martin Lodge Richard Nunns in conversation with Martin Lodge

year: 2008