title: ‘Getting stuck’ in analogue electronics: Threshold concepts as an explanatory model

authors: Harlow, Ann

subjects: threshold concepts

abstract: Could the challenge of mastering threshold concepts be a potential factor that influences a student's decision to continue in electronics engineering? This was the question that led to a collaborative research project between educational researchers and the Faculty of Engineering in a New Zealand university. This paper deals exclusively with the qualitative data from this project, which was designed to investigate the high attrition rate of students taking introductory electronics in a New Zealand university. The affordances of the various teaching opportunities and the barriers that students perceived are examined in the light of recent international research in the area of threshold concepts and transformational learning. Suggestions are made to help students move forward in their thinking, without compromising the need for maintaining the element of intellectual uncertainty that is crucial for tertiary teaching. The issue of the timing of assessments as a measure of conceptual development or the crossing of thresholds is raised.

text: ‘Getting stuck’ in analogue electronics: Threshold concepts as an explanatory model Could the challenge of mastering threshold concepts be a potential factor that influences a student's decision to continue in electronics engineering? This was the question that led to a collaborative research project between educational researchers and the Faculty of Engineering in a New Zealand university. This paper deals exclusively with the qualitative data from this project, which was designed to investigate the high attrition rate of students taking introductory electronics in a New Zealand university. The affordances of the various teaching opportunities and the barriers that students perceived are examined in the light of recent international research in the area of threshold concepts and transformational learning. Suggestions are made to help students move forward in their thinking, without compromising the need for maintaining the element of intellectual uncertainty that is crucial for tertiary teaching. The issue of the timing of assessments as a measure of conceptual development or the crossing of thresholds is raised.

year: 2011

title: Ligand exchange reactions of [Re₂(μ-OR)₃(CO)₆]⁻(R = H, Me) with sulfur, selenium, phosphorus and nitrogen donor ligands, investigated by electrospray mass spectrometry

authors: Jiang, Chenghua

subjects: chemistry

abstract: Negative-ion electrospray mass spectrometry has been used to investigate the reactions of the dinuclear rhenium aggregates [Re₂(μ-OH)₃(CO)₆]⁻ 1 and [Re₂(μ-OMe)₃(CO)₆]⁻ 2 with a range of thiols, benzeneselenol, and some other sulfur-, phosphorus- and nitrogen-based ligands. Typically up to three of the hydroxo ligands are replaced by simple thiolates, giving the series of species [Re₂(OH)₂(SR)(CO)₆]⁻, [Re₂(OH)(SR)₂(CO)₆]⁻, and [Re₂(SR)₃(CO)₆]⁻. Similarly, reaction of 1 with H₂S gives the species [Re₂(μ-SH)₃(CO)₆]⁻, which undergoes an analogous fragmentation process to [Re₂(μ-OH)₃(CO)₆]⁻, at high cone voltages, by loss of H₂S and formation of [Re₂(S)(SH)(CO)₆]⁻. With ligands which are good chelating agents (such as dithiocarbamates R₂NCS₂⁻, and thiosalicylic acid, HSC₆H₄CO₂H) initial substitution of one or two OH groups readily occurs, but on standing the dimer is cleaved giving [Re(S₂CNR₂)₂(CO)₃]⁻ and [Re(SC₆H₄CO₂)(CO)₃]⁻. The different reactivities of the dithiol reagents benzene-1,2- and benzene-1,4-dimethanethiol towards 1 are also described. Complex 1 also reacts with aniline, and with primary (but not secondary) amides RC(O)NH₂, giving monosubstituted species [Re₂(OH)₂(NHPh)(CO)₆]⁻ and [Re₂(OH)₂{NHC(O)R}(CO)₆]⁻ respectively. The reactions with adenine and thymine, and with the inorganic anions thiocyanate and thiosulfate, are also described.

text: Ligand exchange reactions of [Re₂(μ-OR)₃(CO)₆]⁻(R = H, Me) with sulfur, selenium, phosphorus and nitrogen donor ligands, investigated by electrospray mass spectrometry Negative-ion electrospray mass spectrometry has been used to investigate the reactions of the dinuclear rhenium aggregates [Re₂(μ-OH)₃(CO)₆]⁻ 1 and [Re₂(μ-OMe)₃(CO)₆]⁻ 2 with a range of thiols, benzeneselenol, and some other sulfur-, phosphorus- and nitrogen-based ligands. Typically up to three of the hydroxo ligands are replaced by simple thiolates, giving the series of species [Re₂(OH)₂(SR)(CO)₆]⁻, [Re₂(OH)(SR)₂(CO)₆]⁻, and [Re₂(SR)₃(CO)₆]⁻. Similarly, reaction of 1 with H₂S gives the species [Re₂(μ-SH)₃(CO)₆]⁻, which undergoes an analogous fragmentation process to [Re₂(μ-OH)₃(CO)₆]⁻, at high cone voltages, by loss of H₂S and formation of [Re₂(S)(SH)(CO)₆]⁻. With ligands which are good chelating agents (such as dithiocarbamates R₂NCS₂⁻, and thiosalicylic acid, HSC₆H₄CO₂H) initial substitution of one or two OH groups readily occurs, but on standing the dimer is cleaved giving [Re(S₂CNR₂)₂(CO)₃]⁻ and [Re(SC₆H₄CO₂)(CO)₃]⁻. The different reactivities of the dithiol reagents benzene-1,2- and benzene-1,4-dimethanethiol towards 1 are also described. Complex 1 also reacts with aniline, and with primary (but not secondary) amides RC(O)NH₂, giving monosubstituted species [Re₂(OH)₂(NHPh)(CO)₆]⁻ and [Re₂(OH)₂{NHC(O)R}(CO)₆]⁻ respectively. The reactions with adenine and thymine, and with the inorganic anions thiocyanate and thiosulfate, are also described.

year: 2000

title: Tangi and State Funeral: Te Arikinui Dame Te Atairangikaahu and Prime Minister Norman Kirk

authors: McRae, Karyn Okeroa

subjects: Tangi

abstract: The tangi of Te Arikinui Dame Te Atairangikaahu (Te Arikinui) in 2006 paralleled the State funerals for New Zealand Prime Ministers like Norman Kirk who died in 1974. State funerals require the huge mobilization of people and resources and always attract the attention of the national and international media. The death of a Prime Minister is news worthy, but what of a minority indigenous fourth world leader like Te Arikinui? Why did her passing attract so much media attention? In this study I argue that media representation of the tangi of Te Arikinui was largely about social, cultural and symbolic capital. In media saturated societies such as Aotearoa/New Zealand, through mainstream media outlets like TV One News and the Waikato Times, Te Arikinui’s tangi event claimed a dominant space in the lives of Maori and non Maori alike. The data source includes print news media coverage of the tangi of Te Arikinui and the State funeral of Norman Kirk. Descriptive narrative and abductive analysis inform the methodology used in this study. As expected, print media reporting of both events progressed through the three stages identified by Durkheim, those of, separation, liminality and reincorporation. The ownership of death, the deceased and the continued possession of their mortal remains, itself a cultural object with symbolic and cultural capital, reflected the actual power and control of the possessor. State funerals and tangi are about the ritualized performance of grief and mourning, and require the appropriate social, cultural and symbolic capital for its enactment.

text: Tangi and State Funeral: Te Arikinui Dame Te Atairangikaahu and Prime Minister Norman Kirk The tangi of Te Arikinui Dame Te Atairangikaahu (Te Arikinui) in 2006 paralleled the State funerals for New Zealand Prime Ministers like Norman Kirk who died in 1974. State funerals require the huge mobilization of people and resources and always attract the attention of the national and international media. The death of a Prime Minister is news worthy, but what of a minority indigenous fourth world leader like Te Arikinui? Why did her passing attract so much media attention? In this study I argue that media representation of the tangi of Te Arikinui was largely about social, cultural and symbolic capital. In media saturated societies such as Aotearoa/New Zealand, through mainstream media outlets like TV One News and the Waikato Times, Te Arikinui’s tangi event claimed a dominant space in the lives of Maori and non Maori alike. The data source includes print news media coverage of the tangi of Te Arikinui and the State funeral of Norman Kirk. Descriptive narrative and abductive analysis inform the methodology used in this study. As expected, print media reporting of both events progressed through the three stages identified by Durkheim, those of, separation, liminality and reincorporation. The ownership of death, the deceased and the continued possession of their mortal remains, itself a cultural object with symbolic and cultural capital, reflected the actual power and control of the possessor. State funerals and tangi are about the ritualized performance of grief and mourning, and require the appropriate social, cultural and symbolic capital for its enactment.

year: 2010