title: Effect of various chemical treatments on the fibre structure and tensile properties of industrial hemp fibres

authors: Sawpan, Moyeenuddin Ahmad

subjects: fibres

abstract: Industrial hemp fibres were treated with sodium hydroxide, acetic anhydride, maleic anhydride and silane to investigate the influence of treatment on the fibre structure and tensile properties. It was observed that the average tensile strength of sodium hydroxide treated fibres slightly increased compared with that of untreated fibres, which was believed to be as a result of increased cellulose crystallinity. The average tensile strength of acetic anhydride, maleic anhydride, silane and combined sodium hydroxide and silane treated fibres slightly decreased compared with that of untreated fibres, which was believed to be as a result of decreased cellulose crystallinity. However, the average Young’s modulus of all treated fibres increased compared with untreated fibres. This was considered to be as a result of densification of fibre cell walls due to the removal of non-cellulosic components during treatment.

text: Effect of various chemical treatments on the fibre structure and tensile properties of industrial hemp fibres Industrial hemp fibres were treated with sodium hydroxide, acetic anhydride, maleic anhydride and silane to investigate the influence of treatment on the fibre structure and tensile properties. It was observed that the average tensile strength of sodium hydroxide treated fibres slightly increased compared with that of untreated fibres, which was believed to be as a result of increased cellulose crystallinity. The average tensile strength of acetic anhydride, maleic anhydride, silane and combined sodium hydroxide and silane treated fibres slightly decreased compared with that of untreated fibres, which was believed to be as a result of decreased cellulose crystallinity. However, the average Young’s modulus of all treated fibres increased compared with untreated fibres. This was considered to be as a result of densification of fibre cell walls due to the removal of non-cellulosic components during treatment.

year: 2011

title: Validating the depression anxiety stress scales (DASS-21) across Germany, Ghana, India, and New Zealand using Rasch methodology

authors: Adu, P

subjects: Anxiety

abstract: Psychological distress is widespread globally, affects both mental and physical health, and has been significantly exacerbated by the COVID-19 pandemic. Reliable and valid instruments to assess psychological distress are needed so that interventions to address this condition can be directed and evaluated. We evaluated the psychometric statistics of the Depression Anxiety Stress Scales (DASS-21) using the Rasch method and a population survey sample dataset from four nations. To meet the requirements of the Rasch model, we randomly selected 500 participants (at least 110 from each country) from a total sample of 1822 individuals from Germany (n = 475), Ghana (n = 523), India (n = 411), and New Zealand (n = 413). Minor testlet modifications were necessary to achieve a satisfactory model fit for the depression (χ2 (30) = 40.32, p = 0.099), anxiety (χ2 (32) = 31.22, p = 0.510), and stress (χ2 (20) = 29.64, p = 0.076) subscales, and the full-scale (χ2 (18) = 23.93, p = 0.16). The scales were strictly unidimensional with acceptable reliability reflected by Person Separation Index (PSI) values of 0.86 for depression, 0.74 for anxiety, 0.82 for stress, and 0.87 for the total scale. The scales’ items showed invariance across the countries and sociodemographic factors. The scales also demonstrated convergent, structural, and external validities. The study supported the reliability and validity of the DASS-21 for assessing psychological distress in four countries. Rasch model algorithms developed in this study enable conversion of the ordinal DASS-21 scale and its subscale scores to interval-level scores, which increases the precision of measurement. Future studies should apply Rasch methodology to the DASS-21 in various cultural contexts, incorporating subgroup analyses.

text: Validating the depression anxiety stress scales (DASS-21) across Germany, Ghana, India, and New Zealand using Rasch methodology Psychological distress is widespread globally, affects both mental and physical health, and has been significantly exacerbated by the COVID-19 pandemic. Reliable and valid instruments to assess psychological distress are needed so that interventions to address this condition can be directed and evaluated. We evaluated the psychometric statistics of the Depression Anxiety Stress Scales (DASS-21) using the Rasch method and a population survey sample dataset from four nations. To meet the requirements of the Rasch model, we randomly selected 500 participants (at least 110 from each country) from a total sample of 1822 individuals from Germany (n = 475), Ghana (n = 523), India (n = 411), and New Zealand (n = 413). Minor testlet modifications were necessary to achieve a satisfactory model fit for the depression (χ2 (30) = 40.32, p = 0.099), anxiety (χ2 (32) = 31.22, p = 0.510), and stress (χ2 (20) = 29.64, p = 0.076) subscales, and the full-scale (χ2 (18) = 23.93, p = 0.16). The scales were strictly unidimensional with acceptable reliability reflected by Person Separation Index (PSI) values of 0.86 for depression, 0.74 for anxiety, 0.82 for stress, and 0.87 for the total scale. The scales’ items showed invariance across the countries and sociodemographic factors. The scales also demonstrated convergent, structural, and external validities. The study supported the reliability and validity of the DASS-21 for assessing psychological distress in four countries. Rasch model algorithms developed in this study enable conversion of the ordinal DASS-21 scale and its subscale scores to interval-level scores, which increases the precision of measurement. Future studies should apply Rasch methodology to the DASS-21 in various cultural contexts, incorporating subgroup analyses.

year: 2025

title: "He Matapihi ki te Mana Raraunga” - Conceptualising Big Data through a Māori lens

authors: Hudson, Maui

abstract: Advances in computer technology and analytical processes create an environment where data becomes the raw material mined to create valuable information and insights. The idea of Big Data emerges from the collation of increasing vast amounts of data enabled by the shift towards an increasingly open data environment. How this changing context alters the relationship between Iwi/Māori collectives and their mātauranga, cultural information and data has yet to be fully explored. However, the concept of Māori Data Sovereignty, which anticipates Māori governance over Māori data, has a natural appeal. This chapter outlines some of the Māori concepts and presents a framework which may be used to inform how data and data use may be conceptualised through a Māori cultural lens.

text: "He Matapihi ki te Mana Raraunga” - Conceptualising Big Data through a Māori lens Advances in computer technology and analytical processes create an environment where data becomes the raw material mined to create valuable information and insights. The idea of Big Data emerges from the collation of increasing vast amounts of data enabled by the shift towards an increasingly open data environment. How this changing context alters the relationship between Iwi/Māori collectives and their mātauranga, cultural information and data has yet to be fully explored. However, the concept of Māori Data Sovereignty, which anticipates Māori governance over Māori data, has a natural appeal. This chapter outlines some of the Māori concepts and presents a framework which may be used to inform how data and data use may be conceptualised through a Māori cultural lens.

year: 2017