title: Thermal stability of nanocrystalline copper films

authors: Cao, Peng

subjects: nanocrystalline

abstract: The grain growth kinetics of nanocrystalline copper thin film samples was investigated. The grain size of nanocrystalline copper samples was determined from the broadening of X-ray spectra. It was found that the grain size increased linearly with isothermal annealing time within the first 10 minutes, beyond which power-law growth kinetics is applied. The activation energy for grain growth was determined by constructing an Arrhenius plot, which shows an activation energy of about 21 – 30 kJ/mol. The low activation energy is attributed to the second phase particle drag and the porosity drag, which act as the pinning force for grain growth in nanocrystalline copper.

text: Thermal stability of nanocrystalline copper films The grain growth kinetics of nanocrystalline copper thin film samples was investigated. The grain size of nanocrystalline copper samples was determined from the broadening of X-ray spectra. It was found that the grain size increased linearly with isothermal annealing time within the first 10 minutes, beyond which power-law growth kinetics is applied. The activation energy for grain growth was determined by constructing an Arrhenius plot, which shows an activation energy of about 21 – 30 kJ/mol. The low activation energy is attributed to the second phase particle drag and the porosity drag, which act as the pinning force for grain growth in nanocrystalline copper.

year: 2006

title: Ecological response differentials: An alternative benchmark to inform stream and river bioassessment

authors: Collier, Kevin J.

subjects: macroinvertebrate

abstract: Contemporary patterns of land development mean that suitable reference sites for low-gradient stream and non-wadeable river biomonitoring are difficult to locate, requiring alternative approaches for benchmarking human impacts. We use two strongly harmonised macroinvertebrate data sets for wadeable streams (180 sites) and non-wadeable rivers (30 sites) to (i) quantify metric response differentials across a regional landcover pressure gradient in northern New Zealand; (ii) interpolate reference condition for waterway types lacking comparable reference sites and (iii) inform development of narrative condition bands for data-poor waterway types.
Cumulative distribution functions of per cent waterway length indicated that near-shore littoral samples from non-wadeable rivers had fewer total and EPT (Ephemeroptera, Plecoptera and Trichoptera) taxa than wadeable streams, which had higher % EPT abundance and lower % Crustacea abundance. Community composition differed significantly among non-wadeable river and wadeable hard-bottom and soft-bottom stream samples, reflecting factors associated with catchment altitude, slope, rainfall and landuse intensity.
Ephemeroptera, Plecoptera and Trichoptera richness was the only metric evaluated that significantly reflected landcover across all waterway types. The intercept of the 60th percentile quantile regression line at 100% native vegetation cover provided the best approximation of median EPT taxa richness in an independent reference site data set for hard-bottom streams. Applying the same interpolation to samples from soft-bottom streams and non-wadable rivers that lacked regional reference sites indicated median reference expectations of 9 and 11 EPT taxa, respectively, and a consistent differential across the pressure gradient relative to hard-bottom streams of seven taxa and five taxa, respectively.
The derived response differentials enabled the development of narrative bands for directly comparing ecological condition of data-poor stream and river types. Quantification of ecological response differentials can provide an alternative means of benchmarking macroinvertebrate metrics in the absence of suitable reference sites.

text: Ecological response differentials: An alternative benchmark to inform stream and river bioassessment Contemporary patterns of land development mean that suitable reference sites for low-gradient stream and non-wadeable river biomonitoring are difficult to locate, requiring alternative approaches for benchmarking human impacts. We use two strongly harmonised macroinvertebrate data sets for wadeable streams (180 sites) and non-wadeable rivers (30 sites) to (i) quantify metric response differentials across a regional landcover pressure gradient in northern New Zealand; (ii) interpolate reference condition for waterway types lacking comparable reference sites and (iii) inform development of narrative condition bands for data-poor waterway types.
Cumulative distribution functions of per cent waterway length indicated that near-shore littoral samples from non-wadeable rivers had fewer total and EPT (Ephemeroptera, Plecoptera and Trichoptera) taxa than wadeable streams, which had higher % EPT abundance and lower % Crustacea abundance. Community composition differed significantly among non-wadeable river and wadeable hard-bottom and soft-bottom stream samples, reflecting factors associated with catchment altitude, slope, rainfall and landuse intensity.
Ephemeroptera, Plecoptera and Trichoptera richness was the only metric evaluated that significantly reflected landcover across all waterway types. The intercept of the 60th percentile quantile regression line at 100% native vegetation cover provided the best approximation of median EPT taxa richness in an independent reference site data set for hard-bottom streams. Applying the same interpolation to samples from soft-bottom streams and non-wadable rivers that lacked regional reference sites indicated median reference expectations of 9 and 11 EPT taxa, respectively, and a consistent differential across the pressure gradient relative to hard-bottom streams of seven taxa and five taxa, respectively.
The derived response differentials enabled the development of narrative bands for directly comparing ecological condition of data-poor stream and river types. Quantification of ecological response differentials can provide an alternative means of benchmarking macroinvertebrate metrics in the absence of suitable reference sites.

year: 2013

title: Research note: Empirical analysis of ethnic pay gaps in New Zealand

authors: Cochrane, William

abstract: This research note explores the factors contributing to ethnic pay gaps in New Zealand. The emphasis here is on description, as a causal analysis is beyond the capability of the methods used. The gaps between the average (as well as median) hourly wages for the European workforce relative to Māori and Pacific workers are substantial. A statistical analysis by Treasury in 2018 also showed that the ratio in average hourly wages (based on published survey estimates by Stats NZ) for both ethnic groups relative to European had stayed at a similar level for the last decade; as they state “there has been movement from year to year but no consistent upward or downward trend” (Treasury, 2018, p.1).

text: Research note: Empirical analysis of ethnic pay gaps in New Zealand This research note explores the factors contributing to ethnic pay gaps in New Zealand. The emphasis here is on description, as a causal analysis is beyond the capability of the methods used. The gaps between the average (as well as median) hourly wages for the European workforce relative to Māori and Pacific workers are substantial. A statistical analysis by Treasury in 2018 also showed that the ratio in average hourly wages (based on published survey estimates by Stats NZ) for both ethnic groups relative to European had stayed at a similar level for the last decade; as they state “there has been movement from year to year but no consistent upward or downward trend” (Treasury, 2018, p.1).

year: 2023-10-19