title: Isolation and characterization of soda lignin from OPEFB and evaluation of its performance as wood adhesive

authors: Toma, Farhana Sultana

subjects: Black Liquor

abstract: The purpose of this study was to explore the mechanical properties of plywood panels that had been bound with lignin-phenol-formaldehyde (LPF) adhesive. LPF, composed of lignin that was extracted from Oil Palm Empty Fruit Bunch (OPEFB) fiber by soda pulping method and characterized by Fourier Transform Infrared (FT-IR), Nuclear Magnetic Resonance (HNMR), and Thermal Gravimetric Analyzer (TGA) analysis. Then, various compositions of soda lignin (10-50 wt %) were used as a phenol substitute in LPF synthesis. The characteristics of the synthesized adhesive were compared to the properties of phenol formaldehyde (PF) adhesive. Plywood was fabricated with LPF and its mechanical properties were studied and evaluated using industrial standards. The result indicates that the increase of phenol substitution with soda lignin, up to 40%, improves the mechanical properties of plywood. This research demonstrated the use of lignin as a renewable replacement of phenol in PF adhesive formulation.

text: Isolation and characterization of soda lignin from OPEFB and evaluation of its performance as wood adhesive The purpose of this study was to explore the mechanical properties of plywood panels that had been bound with lignin-phenol-formaldehyde (LPF) adhesive. LPF, composed of lignin that was extracted from Oil Palm Empty Fruit Bunch (OPEFB) fiber by soda pulping method and characterized by Fourier Transform Infrared (FT-IR), Nuclear Magnetic Resonance (HNMR), and Thermal Gravimetric Analyzer (TGA) analysis. Then, various compositions of soda lignin (10-50 wt %) were used as a phenol substitute in LPF synthesis. The characteristics of the synthesized adhesive were compared to the properties of phenol formaldehyde (PF) adhesive. Plywood was fabricated with LPF and its mechanical properties were studied and evaluated using industrial standards. The result indicates that the increase of phenol substitution with soda lignin, up to 40%, improves the mechanical properties of plywood. This research demonstrated the use of lignin as a renewable replacement of phenol in PF adhesive formulation.

year: 2023-09

title: Boat electrofishing survey of the Awaiti and Bancrofts canals (Tee Head Canal), Piako River system

authors: Hicks, Brendan J.

abstract: This purpose of this survey of Awaiti and Bancrofts canals was to establish the presence of fish in the canals and to determine their relative density and biomass by boat electrofishing. These canals drain the Kopuatai Peat Dome and adjacent farmland into Tee Head Canal, which is part of the Piako River system in the Waikato Region. Awaiti Canal had patches of the emergent macrophyte Eurasian reed sweet grass (Glyceria maxima) and floating common duckweed (Lemna minor). Bancrofts Canal had dense beds of reed sweet grass and water pepper (Persicaria hydropiper, syn. Polygonum hydropiper) that extended into the water along most of its margin to the extent that the bank was not visible. The water of both canals was tannin-stained, but Bancrofts Canal had heavier staining than Awaiti Canal.
We boat electrofished five sites in Awaiti Canal and five sites in Bancrofts Canal for 10 mins each on 21 February 2018. Water temperature was 24.3°C in Awaiti Canal and 23.1°C in Bancrofts Canal. In Awaiti Canal, ambient electrical conductivity was 313.5 µS cm⁻¹, specific conductivity was 317.6 µS cm⁻¹, and black disc distance was 0.18 m. In Bancrofts Canal, ambient conductivity was 174.3 µS cm⁻¹, and specific conductivity was 180.8 µS cm⁻¹.
We caught 31 fish in total, 28 in Awaiti Canal and 3 in Bancrofts Canal. Species included shortfin eels (Anguilla australis), inanga (Galaxias maculatus), goldfish (Carassius auratus), brown bullhead catfish (Ameiurus nebulosus) and gambusia (Gambusia affinis). Two inanga at site 4 (Awaiti Canal) were retrieved dead on capture, as was the one eel retrieved in Bancrofts Canal.
Fish densities were very low, up to a maximum of 1.02 fish 100 m-2 for all species combined at site 3 in Awaiti Canal. Only gambusia were found alive in Bancrofts Canal. Biomass per site and areal biomass were similarly very low, and this was partly attributable to the small size of individuals, which suggested that, with the exception of gambusia, they were young, newly recruited fish.
Awaiti Canal had a low diversity of small fish species that are generally tolerant of poor water quality. This fish diversity is particularly low considering the close proximity of the sites to the coast (about 30 km from the Firth of Thames). The most diverse fish communities in New Zealand are found close to the coast. Typical mean eel densities in the Waikato River assessed by boat electrofishing were 0.7-1.3 eels 100 m⁻² compared to the mean of 0.12 fish 100 m⁻² (range of 0-0.29 eels 100 m⁻² ) at the five sites Awaiti Canal. Bancroft Canal had only gambusia, and the one shortfin eel found dead could have drifted in or died in the canal, probably as result of low DO concentrations.

text: Boat electrofishing survey of the Awaiti and Bancrofts canals (Tee Head Canal), Piako River system This purpose of this survey of Awaiti and Bancrofts canals was to establish the presence of fish in the canals and to determine their relative density and biomass by boat electrofishing. These canals drain the Kopuatai Peat Dome and adjacent farmland into Tee Head Canal, which is part of the Piako River system in the Waikato Region. Awaiti Canal had patches of the emergent macrophyte Eurasian reed sweet grass (Glyceria maxima) and floating common duckweed (Lemna minor). Bancrofts Canal had dense beds of reed sweet grass and water pepper (Persicaria hydropiper, syn. Polygonum hydropiper) that extended into the water along most of its margin to the extent that the bank was not visible. The water of both canals was tannin-stained, but Bancrofts Canal had heavier staining than Awaiti Canal.
We boat electrofished five sites in Awaiti Canal and five sites in Bancrofts Canal for 10 mins each on 21 February 2018. Water temperature was 24.3°C in Awaiti Canal and 23.1°C in Bancrofts Canal. In Awaiti Canal, ambient electrical conductivity was 313.5 µS cm⁻¹, specific conductivity was 317.6 µS cm⁻¹, and black disc distance was 0.18 m. In Bancrofts Canal, ambient conductivity was 174.3 µS cm⁻¹, and specific conductivity was 180.8 µS cm⁻¹.
We caught 31 fish in total, 28 in Awaiti Canal and 3 in Bancrofts Canal. Species included shortfin eels (Anguilla australis), inanga (Galaxias maculatus), goldfish (Carassius auratus), brown bullhead catfish (Ameiurus nebulosus) and gambusia (Gambusia affinis). Two inanga at site 4 (Awaiti Canal) were retrieved dead on capture, as was the one eel retrieved in Bancrofts Canal.
Fish densities were very low, up to a maximum of 1.02 fish 100 m-2 for all species combined at site 3 in Awaiti Canal. Only gambusia were found alive in Bancrofts Canal. Biomass per site and areal biomass were similarly very low, and this was partly attributable to the small size of individuals, which suggested that, with the exception of gambusia, they were young, newly recruited fish.
Awaiti Canal had a low diversity of small fish species that are generally tolerant of poor water quality. This fish diversity is particularly low considering the close proximity of the sites to the coast (about 30 km from the Firth of Thames). The most diverse fish communities in New Zealand are found close to the coast. Typical mean eel densities in the Waikato River assessed by boat electrofishing were 0.7-1.3 eels 100 m⁻² compared to the mean of 0.12 fish 100 m⁻² (range of 0-0.29 eels 100 m⁻² ) at the five sites Awaiti Canal. Bancroft Canal had only gambusia, and the one shortfin eel found dead could have drifted in or died in the canal, probably as result of low DO concentrations.

year: 2018

title: Maori women and research: Researching ourselves

authors: Te Awekotuku, Ngahuia

subjects: Maori

abstract: This was the closing keynote address at the Student Symposium organized by the Maori &
Psychology Research Unit at the University of Waikato, Hamilton in August 1999. Most of the
people attending were Maori, and female, and I spoke to, for, and about us. The speech was
transcribed from an oral address with transparencies, and has been revised here for this
publication.

text: Maori women and research: Researching ourselves This was the closing keynote address at the Student Symposium organized by the Maori &
Psychology Research Unit at the University of Waikato, Hamilton in August 1999. Most of the
people attending were Maori, and female, and I spoke to, for, and about us. The speech was
transcribed from an oral address with transparencies, and has been revised here for this
publication.

year: 1999