title: A study on rhodium and palladium mixed-media sols

authors: Jaine, Jacob Evan

subjects: colloid

abstract: Historically the majority of precious metal sols have been prepared in an aqueous medium, while a much smaller proportion have been prepared in various non‐aqueous solvents. Few however have been prepared in mixtures of the two, this paucity being the raison d’être of this study. The goal therefore was to perform a systematic investigation of the changes in the properties of rhodium and palladium sols generated in mixtures of water and another organic cosolvent across a range of volumetric compositions. Six cosolvents were investigated: methanol, dimethylsulfoxide, acetonitrile, N,N‐dimethylformamide, acetone, and tetrahydrofuran. To stabilise the resulting sols against aggregation four protecting agents were used: poly(vinyl pyrrolidone), poly(vinyl alcohol), poly(acrylic acid), and arabinogalactan, which was a newly‐available polysaccharide extracted from the Western Larch tree. To reduce the metals from their precursor salts, sodium borohydride and hydrazine hydrate were used. The resulting colloids were analysed by Transmission Electron Microscopy (TEM), Photon Correlation Spectroscopy (PCS) and Ultraviolet/Visible Spectrophotometry. The size of the primary particles in the resulting sols was shown by TEM to be inversely proportional to the proportion of cosolvent in which they were generated. A theory was postulated to account for these changes based on temporary stabilisation of the metal nuclei by adsorption of cosolvent molecules. The characteristics of the aggregates observed in the TEM micrographs were shown to be independent of the cosolvent proportion, changing progressively but unpredictably across the composition ranges studied for most systems. This behaviour was believed to be caused by changes in the conformations of the protecting agents, which depended nonlinearly on the composition of the dispersion medium in which they were used. The measurements collected in‐situ by both PCS and UV/Vis were considered to be good indicators of the levels of aggregation observed in the sols ex‐situ by TEM, with any disparities between the two sets of measurements rationalised with relative ease. PCS measurements gave average hydrodynamic diameters of approximately 20 nm – 80 nm for sols generated in purely aqueous dispersion media, depending on the metal and protecting agent used. Infrared spectra were collected of carbon monoxide adsorbed to the surface of the particles of the sols in mixed‐media to determine the effect of the cosolvent proportion on ν(CO)ads. Sols generated for the aforementioned work were found to be of insufficient density for this purpose, so a series of high‐density sols were synthesised especially. Adsorbed CO was successfully detected on rhodium sols in mixtures of water and either MeOH, DMF, DMSO or MeCN. In these cases υ(CO)ads and its intensity decreased as the cosolvent proportion was increased. This behaviour was rationalised by competitive adsorption of the cosolvent molecules onto the surface of the colloidal particles, precluding the adsorption of CO molecules. The consequent decrease in surface coverage was presumed to have lead to a loss of dipolar coupling, affecting the stretching frequency. These data were used to support the theory postulated for the decrease in the average particle size of the sols generated in mixed‐media.

text: A study on rhodium and palladium mixed-media sols Historically the majority of precious metal sols have been prepared in an aqueous medium, while a much smaller proportion have been prepared in various non‐aqueous solvents. Few however have been prepared in mixtures of the two, this paucity being the raison d’être of this study. The goal therefore was to perform a systematic investigation of the changes in the properties of rhodium and palladium sols generated in mixtures of water and another organic cosolvent across a range of volumetric compositions. Six cosolvents were investigated: methanol, dimethylsulfoxide, acetonitrile, N,N‐dimethylformamide, acetone, and tetrahydrofuran. To stabilise the resulting sols against aggregation four protecting agents were used: poly(vinyl pyrrolidone), poly(vinyl alcohol), poly(acrylic acid), and arabinogalactan, which was a newly‐available polysaccharide extracted from the Western Larch tree. To reduce the metals from their precursor salts, sodium borohydride and hydrazine hydrate were used. The resulting colloids were analysed by Transmission Electron Microscopy (TEM), Photon Correlation Spectroscopy (PCS) and Ultraviolet/Visible Spectrophotometry. The size of the primary particles in the resulting sols was shown by TEM to be inversely proportional to the proportion of cosolvent in which they were generated. A theory was postulated to account for these changes based on temporary stabilisation of the metal nuclei by adsorption of cosolvent molecules. The characteristics of the aggregates observed in the TEM micrographs were shown to be independent of the cosolvent proportion, changing progressively but unpredictably across the composition ranges studied for most systems. This behaviour was believed to be caused by changes in the conformations of the protecting agents, which depended nonlinearly on the composition of the dispersion medium in which they were used. The measurements collected in‐situ by both PCS and UV/Vis were considered to be good indicators of the levels of aggregation observed in the sols ex‐situ by TEM, with any disparities between the two sets of measurements rationalised with relative ease. PCS measurements gave average hydrodynamic diameters of approximately 20 nm – 80 nm for sols generated in purely aqueous dispersion media, depending on the metal and protecting agent used. Infrared spectra were collected of carbon monoxide adsorbed to the surface of the particles of the sols in mixed‐media to determine the effect of the cosolvent proportion on ν(CO)ads. Sols generated for the aforementioned work were found to be of insufficient density for this purpose, so a series of high‐density sols were synthesised especially. Adsorbed CO was successfully detected on rhodium sols in mixtures of water and either MeOH, DMF, DMSO or MeCN. In these cases υ(CO)ads and its intensity decreased as the cosolvent proportion was increased. This behaviour was rationalised by competitive adsorption of the cosolvent molecules onto the surface of the colloidal particles, precluding the adsorption of CO molecules. The consequent decrease in surface coverage was presumed to have lead to a loss of dipolar coupling, affecting the stretching frequency. These data were used to support the theory postulated for the decrease in the average particle size of the sols generated in mixed‐media.

year: 2011

title: Defying the Odds: Gifted and Talented Young People from Low Socioeconomic Backgrounds

authors: Ballam, Nadine Dawn

subjects: Gifted and talented

abstract: The aim of this study was to explore the lived experiences of gifted and talented New Zealand young people from low socioeconomic backgrounds, with an emphasis on risk and protective processes that might foster resilience.  Ninety-three young people between the ages of 17 and 27 participated in this study, each having been identified as gifted in one or more of the following areas: academic, sporting, creative arts, and leadership.  

The participants were sourced from First Foundation, an organisation that awards scholarships to gifted New Zealand secondary school students who come from financially disadvantaged backgrounds.  At the time this research was undertaken, there were 181 past and present First Foundation scholarship recipients, and invitations to participate were extended to each of these young people. 

The qualitative methodology considered to be most appropriate for this study was Interpretative Phenomenological Analysis (IPA), as it allows the researcher to get an ‘inside perspective’ of how individuals make meaning of their experiences (Smith & Osborn, 2008).  This study involved an anonymous electronic survey of 93 gifted young people, and a further eight in depth interviews.  The survey and interview questions focused on broad themes related to the participants’ giftedness and personal circumstances, including: their talents and interests; their education and schooling; the influence of family and friends; the presence of role models and mentors; and their childhood experiences.

‘Identity’ was one of three key themes that emerged from this study.  One of the most significant findings was that the limitations of being gifted presented as more of a risk factor than limitations associated with personal circumstances, particularly in relation to a sense of identity.  This finding contradicts numerous other studies that focus on the relationship between giftedness and low socioeconomic status.  

Many studies of gifted individuals suggest that ‘drive’, which emerged as a second key theme, is common amongst those who achieve to significant levels.  In this study, however, the majority of participants reported that their drive was directly related to the socioeconomic challenges they had faced.  For many, their drive translated into a strong desire to use their gifts and talents to benefit others facing similar challenges.

‘Opportunities’ were also considered crucial for enabling the talent development process and many of the young people in this study indicated that relationships with other people rather than material opportunities had been most valuable.  The opportunistic natures of the participants also enabled them to recognise, seek out, and make the most of opportunities, despite the limitations of their socioeconomic circumstances. 

Little is known about how gifted New Zealanders from financially challenging backgrounds fare in terms of their talent development and this research addresses recent calls for investigation in this area.  The findings from this study contribute broadly to existing knowledge about gifted and talented learners in New Zealand, and provide specific insight into the lived experiences of those from socioeconomically challenging backgrounds.  One significant finding is the nature of risk and resilience processes operating amongst this group of young people, which may serve to extend understanding of how gifted individuals who face adversity are able to develop their talents.  There are also important implications that arise from this study for those who live and work with gifted young people from low socioeconomic backgrounds.

text: Defying the Odds: Gifted and Talented Young People from Low Socioeconomic Backgrounds The aim of this study was to explore the lived experiences of gifted and talented New Zealand young people from low socioeconomic backgrounds, with an emphasis on risk and protective processes that might foster resilience.  Ninety-three young people between the ages of 17 and 27 participated in this study, each having been identified as gifted in one or more of the following areas: academic, sporting, creative arts, and leadership.  

The participants were sourced from First Foundation, an organisation that awards scholarships to gifted New Zealand secondary school students who come from financially disadvantaged backgrounds.  At the time this research was undertaken, there were 181 past and present First Foundation scholarship recipients, and invitations to participate were extended to each of these young people. 

The qualitative methodology considered to be most appropriate for this study was Interpretative Phenomenological Analysis (IPA), as it allows the researcher to get an ‘inside perspective’ of how individuals make meaning of their experiences (Smith & Osborn, 2008).  This study involved an anonymous electronic survey of 93 gifted young people, and a further eight in depth interviews.  The survey and interview questions focused on broad themes related to the participants’ giftedness and personal circumstances, including: their talents and interests; their education and schooling; the influence of family and friends; the presence of role models and mentors; and their childhood experiences.

‘Identity’ was one of three key themes that emerged from this study.  One of the most significant findings was that the limitations of being gifted presented as more of a risk factor than limitations associated with personal circumstances, particularly in relation to a sense of identity.  This finding contradicts numerous other studies that focus on the relationship between giftedness and low socioeconomic status.  

Many studies of gifted individuals suggest that ‘drive’, which emerged as a second key theme, is common amongst those who achieve to significant levels.  In this study, however, the majority of participants reported that their drive was directly related to the socioeconomic challenges they had faced.  For many, their drive translated into a strong desire to use their gifts and talents to benefit others facing similar challenges.

‘Opportunities’ were also considered crucial for enabling the talent development process and many of the young people in this study indicated that relationships with other people rather than material opportunities had been most valuable.  The opportunistic natures of the participants also enabled them to recognise, seek out, and make the most of opportunities, despite the limitations of their socioeconomic circumstances. 

Little is known about how gifted New Zealanders from financially challenging backgrounds fare in terms of their talent development and this research addresses recent calls for investigation in this area.  The findings from this study contribute broadly to existing knowledge about gifted and talented learners in New Zealand, and provide specific insight into the lived experiences of those from socioeconomically challenging backgrounds.  One significant finding is the nature of risk and resilience processes operating amongst this group of young people, which may serve to extend understanding of how gifted individuals who face adversity are able to develop their talents.  There are also important implications that arise from this study for those who live and work with gifted young people from low socioeconomic backgrounds.

year: 2013

title: Ue Waerea

authors: Tuaupiki, Jackie Whetumarama

subjects: Waerea

abstract: Mai i Mōkau ki Tāmaki, Mangatoatoa, Pare-Waikato, Pare-Hauraki, Te Kaokaoroa o Pātetere, ko te whakapono, nā Tāwhaki i piki te poutama ki te tāhuhu matapu, ka riro mai i a ia ngā kete o te wānanga. E kīngia ai, ko te pūtake tērā o te mātauranga Māori. Hei tā Wiri (2001), nā te mātauranga Māori, ko te mātauranga Māori ā-waha. Nāna, ko te waiata. Nā te waiata, ko te karakia. Kei raro i te karakia, ko te takere kaupapa tēnei, ko te waerea. Ko te whāinga o tēnei tuhituhinga, he rangahau i ngā pūtake o te waerea me te āta titiro ki ngā kaupapa kei a ia me tōna kawe i roto i aua kaupapa i ngā wā o mua, ā, nō nāianei hoki. Ko te waerea te pane o ngā karakia Māori ki roto o Tainui, otirā, ki roto i ngētehi o ngā whakaritenga, ā, ka tirohia ngēnei whakaritenga e rere ai te waerea, pēnei i te tomo whare, i te tomo urupā, i te takahi whare, i te whakamānu waka me te maha o ngā mahi a te ao Māori ki roto o Tainui.

text: Ue Waerea Mai i Mōkau ki Tāmaki, Mangatoatoa, Pare-Waikato, Pare-Hauraki, Te Kaokaoroa o Pātetere, ko te whakapono, nā Tāwhaki i piki te poutama ki te tāhuhu matapu, ka riro mai i a ia ngā kete o te wānanga. E kīngia ai, ko te pūtake tērā o te mātauranga Māori. Hei tā Wiri (2001), nā te mātauranga Māori, ko te mātauranga Māori ā-waha. Nāna, ko te waiata. Nā te waiata, ko te karakia. Kei raro i te karakia, ko te takere kaupapa tēnei, ko te waerea. Ko te whāinga o tēnei tuhituhinga, he rangahau i ngā pūtake o te waerea me te āta titiro ki ngā kaupapa kei a ia me tōna kawe i roto i aua kaupapa i ngā wā o mua, ā, nō nāianei hoki. Ko te waerea te pane o ngā karakia Māori ki roto o Tainui, otirā, ki roto i ngētehi o ngā whakaritenga, ā, ka tirohia ngēnei whakaritenga e rere ai te waerea, pēnei i te tomo whare, i te tomo urupā, i te takahi whare, i te whakamānu waka me te maha o ngā mahi a te ao Māori ki roto o Tainui.

year: 2011-04