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: Maxing Out in China: Optimism or Attention?

authors: Cheema, Muhammad A.

abstract: Bali et al. (2011) document a maximum daily returns (MAX) premium in the US where stocks with the highest MAX underperform stocks with the lowest MAX in the subsequent month. However, the source of this MAX premium is contentious. Fong and Toh (2014) find that the MAX premium exclusively follows high sentiment periods suggesting that it is driven by investor optimism during high sentiment periods. In contrast Cheon and Lee (2017) find that the MAX premium is stronger following low sentiment periods suggesting that it is driven by the attention-grabbing characteristic of high MAX stocks in low sentiment periods. We present evidence from China consistent with the MAX premium being driven by investor optimism during high sentiment periods.

text: Maxing Out in China: Optimism or Attention? Bali et al. (2011) document a maximum daily returns (MAX) premium in the US where stocks with the highest MAX underperform stocks with the lowest MAX in the subsequent month. However, the source of this MAX premium is contentious. Fong and Toh (2014) find that the MAX premium exclusively follows high sentiment periods suggesting that it is driven by investor optimism during high sentiment periods. In contrast Cheon and Lee (2017) find that the MAX premium is stronger following low sentiment periods suggesting that it is driven by the attention-grabbing characteristic of high MAX stocks in low sentiment periods. We present evidence from China consistent with the MAX premium being driven by investor optimism during high sentiment periods.

year: 2018

title: An evaluation of Te Rau Puawai workforce 100: Addressing the recruitment and retention of Maori students in tertiary education institutions: A literature review

authors: Nikora, Linda Waimarie

subjects: Maori students

abstract: To evaluate the Te Rau Puawai programme, the Ministry of Health commissioned the
Maori and Psychology Research Unit of the University of Waikato in July 2001. The
overall aim of the evaluation was to provide the Ministry with a clearer understanding
of the programme including: the perceived critical success factors, the barriers if any
regarding Te Rau Puawai, the impact of the programme, the extent to which the
programme may be transferable, gaps in the programme, and suggested
improvements.
To achieve this end, a review of relevant literature was undertaken to provide a
framework to understand the patterns that arose from the information that we
collected as part of this evaluation.
The review of literature is presented in this technical report.

text: An evaluation of Te Rau Puawai workforce 100: Addressing the recruitment and retention of Maori students in tertiary education institutions: A literature review To evaluate the Te Rau Puawai programme, the Ministry of Health commissioned the
Maori and Psychology Research Unit of the University of Waikato in July 2001. The
overall aim of the evaluation was to provide the Ministry with a clearer understanding
of the programme including: the perceived critical success factors, the barriers if any
regarding Te Rau Puawai, the impact of the programme, the extent to which the
programme may be transferable, gaps in the programme, and suggested
improvements.
To achieve this end, a review of relevant literature was undertaken to provide a
framework to understand the patterns that arose from the information that we
collected as part of this evaluation.
The review of literature is presented in this technical report.

year: 2002-05-01