title: Equilibrium moisture content of radiata pine at elevated temperature and pressure reveals measurement challenges

authors: Pearson, Hamish

subjects: water-vapor

abstract: Relatively few studies have been performed on the equilibrium moisture content (EMC) of wood under conditions of elevated temperature and pressure. Eight studies indicated that EMC near saturation decreased between 100 and 150 A degrees C, whilst five studies indicated that EMC increased. The aim of this study was to identify the likely source of the disagreement using radiata pine (Pinus radiata D. Don) sapwood which was conditioned to a moisture content of around 3 % and then exposed for 1 h at 150 A degrees C and relative humidities of either 50, 70 or 90 %. Mean values of EMC, obtained through in situ gravimetric analyses, were 5.7, 7.6 and 12.6 % with 95 % confidence intervals of the order of 1 %. In two further experiments, the humidity was allowed to rise briefly above 90 % and the moisture content after 1 h was found to be > 30 % as in the five studies that indicated EMC increased above 100 A degrees C. The high moisture contents were attributed to condensation of liquid water on the specimen with subsequent evaporation at a rate that was too slow for the moisture content to reach equilibrium before it was measured. Reliable EMC data at elevated temperatures require (1) tight process control of experimental conditions with minimal standard error, (2) specimens with low initial moisture content to avoid unwanted wood mass loss over time, (3) a relative humidity upper limit that avoids drift above 95 %, and (4) extrapolation of data to humidity approaching 100 %.

text: Equilibrium moisture content of radiata pine at elevated temperature and pressure reveals measurement challenges Relatively few studies have been performed on the equilibrium moisture content (EMC) of wood under conditions of elevated temperature and pressure. Eight studies indicated that EMC near saturation decreased between 100 and 150 A degrees C, whilst five studies indicated that EMC increased. The aim of this study was to identify the likely source of the disagreement using radiata pine (Pinus radiata D. Don) sapwood which was conditioned to a moisture content of around 3 % and then exposed for 1 h at 150 A degrees C and relative humidities of either 50, 70 or 90 %. Mean values of EMC, obtained through in situ gravimetric analyses, were 5.7, 7.6 and 12.6 % with 95 % confidence intervals of the order of 1 %. In two further experiments, the humidity was allowed to rise briefly above 90 % and the moisture content after 1 h was found to be > 30 % as in the five studies that indicated EMC increased above 100 A degrees C. The high moisture contents were attributed to condensation of liquid water on the specimen with subsequent evaporation at a rate that was too slow for the moisture content to reach equilibrium before it was measured. Reliable EMC data at elevated temperatures require (1) tight process control of experimental conditions with minimal standard error, (2) specimens with low initial moisture content to avoid unwanted wood mass loss over time, (3) a relative humidity upper limit that avoids drift above 95 %, and (4) extrapolation of data to humidity approaching 100 %.

year: 2013

title: Self-value, belonging, and EAL migrants

authors: Lee, Jinah

abstract: Here I discuss main findings from my Ph.D. research into English as an additional language (EAL) learner identities, in the process inquiring into our practices as EAL education providers and educators.

text: Self-value, belonging, and EAL migrants Here I discuss main findings from my Ph.D. research into English as an additional language (EAL) learner identities, in the process inquiring into our practices as EAL education providers and educators.

year: 2017

title: 1999 Professorial Address: Nau te rourou, naku te rourou… Māori education: setting an agenda.

authors: Bishop, Russell

subjects: educational outcomes

abstract: Current educational policies and practices in Aotearoa/New Zealand were developed and continue to be developed within a framework of power imbalances, which effects Maori the greatest. An alternative model that seeks to address indigenous Māori aspirations and Treaty of Waitangi guarantees for self determination is presented here. This model suggests how a tertiary teacher education institution might create learning contexts wherein power-sharing images, principles and practices will facilitate successful participation by Māori students in mainstream classrooms. This model constitutes the classroom as a place where young people's sense-making processes (cultures) are incorporated and enhanced, where the existing knowledges of young people are seen as "acceptable" and "official" and where the teacher interacts with students in such a way that new knowledge is co-created. Such a classroom will generate totally different interaction and participation patterns and educational outcomes from a classroom where knowledge is seen as something that the teacher makes sense of and then passes on to students.

text: 1999 Professorial Address: Nau te rourou, naku te rourou… Māori education: setting an agenda. Current educational policies and practices in Aotearoa/New Zealand were developed and continue to be developed within a framework of power imbalances, which effects Maori the greatest. An alternative model that seeks to address indigenous Māori aspirations and Treaty of Waitangi guarantees for self determination is presented here. This model suggests how a tertiary teacher education institution might create learning contexts wherein power-sharing images, principles and practices will facilitate successful participation by Māori students in mainstream classrooms. This model constitutes the classroom as a place where young people's sense-making processes (cultures) are incorporated and enhanced, where the existing knowledges of young people are seen as "acceptable" and "official" and where the teacher interacts with students in such a way that new knowledge is co-created. Such a classroom will generate totally different interaction and participation patterns and educational outcomes from a classroom where knowledge is seen as something that the teacher makes sense of and then passes on to students.

year: 2000