title: Estimating evaporation for low wind speeds at an eddy correlation site: potential for windbreak evaluation

authors: Bardsley, W. Earl

subjects: evaporation

abstract: Creating new windbreaks may reduce lee evaporation by reducing surface wind speed (u). However, applying theoretical models to anticipate the extent of evaporation reduction may be liable to error because the physical processes of windbreak evaporative impacts are not fully understood.

text: Estimating evaporation for low wind speeds at an eddy correlation site: potential for windbreak evaluation Creating new windbreaks may reduce lee evaporation by reducing surface wind speed (u). However, applying theoretical models to anticipate the extent of evaporation reduction may be liable to error because the physical processes of windbreak evaporative impacts are not fully understood.

year: 2019

title: Fragmentation pathways of [Re₂(μ-OR)₃(CO)₆]– (R = H, Me) and ligand exchange reactions with oxygen donor ligands, investigated by electrospray mass spectrometry

authors: Jiang, Chenghua

subjects: chemistry

abstract: The rhenium hydroxy and methoxy carbonyl complexes [Re₂(μOR)₃(CO)₆]⁻ (R = H or Me) have been studied by negative-ion electrospray mass spectrometry (ESMS). The complexes undergo facile exchange reactions with protic compounds, including alcohols and phenols. With dimethyl malonate, ester hydrolysis occurs giving carboxylate-containing complexes, and with H₂O₂ or ButOOH, oxidation to ReO₄⁻occurs. The feasibility and extent of these reactions can conveniently, rapidly, and unambiguously be determined by electrospray mass spectrometry, and is dependent on the acidity and steric bulk of the protic compound. The results also suggest that the complexes can be used as versatile starting materials for the synthesis of a wide range of analogous [Re₂(μ-OR)₃(CO)₆]⁻ complexes by simple reaction with an excess of the appropriate alcohol. By varying the applied cone voltage the fragmentation pathways have been investigated; the hydroxy complex undergoes dehydration followed by CO loss, whereas for the methoxy complex  -hydride elimination (and CO loss) is observed, with confirmation provided by deuterium labelling studies. Under ESMS conditions, the neutral complexes [Re₂(μ-OR)₂(μ-dppf )(CO)₆] [R = H or Me; dppf = 1,1 -bis(diphenylphosphino)ferrocene] undergo substantial solvolysis and hydrolysis to give mainly mononuclear species; simple parent ions (e.g. [M + H]⁺) are not formed in appreciable abundance, probably due to the lack of an efficient ionisation pathway.

text: Fragmentation pathways of [Re₂(μ-OR)₃(CO)₆]– (R = H, Me) and ligand exchange reactions with oxygen donor ligands, investigated by electrospray mass spectrometry The rhenium hydroxy and methoxy carbonyl complexes [Re₂(μOR)₃(CO)₆]⁻ (R = H or Me) have been studied by negative-ion electrospray mass spectrometry (ESMS). The complexes undergo facile exchange reactions with protic compounds, including alcohols and phenols. With dimethyl malonate, ester hydrolysis occurs giving carboxylate-containing complexes, and with H₂O₂ or ButOOH, oxidation to ReO₄⁻occurs. The feasibility and extent of these reactions can conveniently, rapidly, and unambiguously be determined by electrospray mass spectrometry, and is dependent on the acidity and steric bulk of the protic compound. The results also suggest that the complexes can be used as versatile starting materials for the synthesis of a wide range of analogous [Re₂(μ-OR)₃(CO)₆]⁻ complexes by simple reaction with an excess of the appropriate alcohol. By varying the applied cone voltage the fragmentation pathways have been investigated; the hydroxy complex undergoes dehydration followed by CO loss, whereas for the methoxy complex  -hydride elimination (and CO loss) is observed, with confirmation provided by deuterium labelling studies. Under ESMS conditions, the neutral complexes [Re₂(μ-OR)₂(μ-dppf )(CO)₆] [R = H or Me; dppf = 1,1 -bis(diphenylphosphino)ferrocene] undergo substantial solvolysis and hydrolysis to give mainly mononuclear species; simple parent ions (e.g. [M + H]⁺) are not formed in appreciable abundance, probably due to the lack of an efficient ionisation pathway.

year: 2000

title: A step into the light: developing a culturally appropriate research prcoess to study Maori Rangatahi perspectives of leisure in one setting.

authors: Harvey, Geraldine

subjects: research -- methodology

abstract: There is little knowledge of Maori peoples' leisure understandings, experiences and participation. This article reports on the development of a culturally appropriate research process that investigated the leisure participation, perspectives, and experiences of five Rotorua Maori Rangatahi in one research setting'. Within this exploration there is a focus on the need to conduct leisure research with Maori people in culturally appropriate ways. This research approach incorporates focus group methodology within a Kaupapa Maori research framework which addresses issues of research for Maori. The research process revealed that focus group methodology can be adapted into a Kaupapa Maori research framework and that this research approach could be an important tool when conducting research with Maori Rangatahi, including in educational contexts.

text: A step into the light: developing a culturally appropriate research prcoess to study Maori Rangatahi perspectives of leisure in one setting. There is little knowledge of Maori peoples' leisure understandings, experiences and participation. This article reports on the development of a culturally appropriate research process that investigated the leisure participation, perspectives, and experiences of five Rotorua Maori Rangatahi in one research setting'. Within this exploration there is a focus on the need to conduct leisure research with Maori people in culturally appropriate ways. This research approach incorporates focus group methodology within a Kaupapa Maori research framework which addresses issues of research for Maori. The research process revealed that focus group methodology can be adapted into a Kaupapa Maori research framework and that this research approach could be an important tool when conducting research with Maori Rangatahi, including in educational contexts.

year: 2002