title: Evaluating input standards for non-point pollution control under firm heterogeneity

authors: Doole, Graeme J.

subjects: firm heterogeneity

abstract: The efficacy and cost of input standards for reducing nitrate pollution from New Zealand dairy production are evaluated. In contrast to previous studies, firm heterogeneity is explicitly considered through the novel integration of efficient techniques for the calibration and decomposition of large optimisation models. Nitrogen fertiliser application should not be targeted by policy given its minor role in determining emissions. In contrast, livestock intensity is an appropriate base for regulation given its strong correlation with pollutant load. Abatement cost increases as stocking rate declines, but this can be offset at low levels of regulation through utilising slack feed resources to improve per-cow milk production. Both uniform and differentiated input standards based on livestock intensity achieve substantial decreases in pollutant load at moderate cost. However, because of disparity in the slopes of abatement cost curves across firms, a differentiated policy is more cost-effective at the levels of regulation required to achieve key societal goals for improved water quality.

text: Evaluating input standards for non-point pollution control under firm heterogeneity The efficacy and cost of input standards for reducing nitrate pollution from New Zealand dairy production are evaluated. In contrast to previous studies, firm heterogeneity is explicitly considered through the novel integration of efficient techniques for the calibration and decomposition of large optimisation models. Nitrogen fertiliser application should not be targeted by policy given its minor role in determining emissions. In contrast, livestock intensity is an appropriate base for regulation given its strong correlation with pollutant load. Abatement cost increases as stocking rate declines, but this can be offset at low levels of regulation through utilising slack feed resources to improve per-cow milk production. Both uniform and differentiated input standards based on livestock intensity achieve substantial decreases in pollutant load at moderate cost. However, because of disparity in the slopes of abatement cost curves across firms, a differentiated policy is more cost-effective at the levels of regulation required to achieve key societal goals for improved water quality.

year: 2010

title: Long‐term residual properties and durability of glass fiber reinforced polymer composite exposed to alkaline solution and natural weather for a decade

authors: Ahmad Sawpan, Moyeenuddin

abstract: This paper presents a comprehensive analysis of the residual thermal and mechanical properties of pultruded glass fiber reinforced polymer composite bars following a decade of conditioning in an alkaline solution and exposure to natural weather conditions. The study focuses on evaluating the changes in the glass transition temperature (Tg) of the polymer matrix and its impact on the bar's mechanical performance. The results indicate that the Tg retained approximately 94.7% of its initial value, with the decrease attributed to the plasticizing effect of absorbed water. The flexural modulus, flexural strength, and transverse shear strength were found to retain 91.8%, 77.2%, and 97.3% of their original values, respectively. The reductions in strength and stiffness were primarily attributed to a weakening in the bonding between the fibers and the polymer matrix. Fractographic analysis revealed that the failure of the plasticized and softened polymer matrix contributed to the observed reductions in strength. Interestingly, the short beam shear strength remained relatively unchanged, as the diffusion of water into the core of the bars at ambient temperatures had a minimal effect. This slower water diffusion in the core led to insignificant degradation of the short beam shear strength.

Highlights
○ GFRP bars were exposed to alkaline solution and natural weather for a decade.
○ The water diffusion was a key factor in determining the residual properties of the GFRP bars.
○ The absorbed water plasticises the polymer matrix in GFRP bars.
○ The mechanical property losses in GFRP bars were associated with changes in the matrix property.

text: Long‐term residual properties and durability of glass fiber reinforced polymer composite exposed to alkaline solution and natural weather for a decade This paper presents a comprehensive analysis of the residual thermal and mechanical properties of pultruded glass fiber reinforced polymer composite bars following a decade of conditioning in an alkaline solution and exposure to natural weather conditions. The study focuses on evaluating the changes in the glass transition temperature (Tg) of the polymer matrix and its impact on the bar's mechanical performance. The results indicate that the Tg retained approximately 94.7% of its initial value, with the decrease attributed to the plasticizing effect of absorbed water. The flexural modulus, flexural strength, and transverse shear strength were found to retain 91.8%, 77.2%, and 97.3% of their original values, respectively. The reductions in strength and stiffness were primarily attributed to a weakening in the bonding between the fibers and the polymer matrix. Fractographic analysis revealed that the failure of the plasticized and softened polymer matrix contributed to the observed reductions in strength. Interestingly, the short beam shear strength remained relatively unchanged, as the diffusion of water into the core of the bars at ambient temperatures had a minimal effect. This slower water diffusion in the core led to insignificant degradation of the short beam shear strength.

Highlights
○ GFRP bars were exposed to alkaline solution and natural weather for a decade.
○ The water diffusion was a key factor in determining the residual properties of the GFRP bars.
○ The absorbed water plasticises the polymer matrix in GFRP bars.
○ The mechanical property losses in GFRP bars were associated with changes in the matrix property.

year: 2023-10-09

title: Consciousness-centered stewardship: An indigenous standpoint

authors: Spiller, Chellie

abstract: Dominion-driven stewardship, which stages human interventions with an anthropocentric lens, externalises problems. We present consciousness-centered stewardship, seen through the Māori ethic of kaitiakitanga, as the missing connective tissue that looks to fix ourselves. We advocate an approach that appreciates a collective self-intelligence in the world and being a steward with a “conscious mind” as part of a transformative way forward. Sustainable development from this perspective thus includes paying attention to personal growth.

text: Consciousness-centered stewardship: An indigenous standpoint Dominion-driven stewardship, which stages human interventions with an anthropocentric lens, externalises problems. We present consciousness-centered stewardship, seen through the Māori ethic of kaitiakitanga, as the missing connective tissue that looks to fix ourselves. We advocate an approach that appreciates a collective self-intelligence in the world and being a steward with a “conscious mind” as part of a transformative way forward. Sustainable development from this perspective thus includes paying attention to personal growth.

year: 2025