title: Composite Cold-Formed Steel Beams with Diagonal Rebars for Earthquake-Resistant Buildings

authors: Samuel, James

subjects: cold-formed steel

abstract: The construction industry is on the lookout for cost-effective structural members that are also environmentally friendly. Built-up cold-formed steel (CFS) sections with minimal thickness can be used to make beams at a lower cost. Plate buckling in CFS beams with thin webs can be avoided by using thick webs, adding stiffeners, or strengthening the web with diagonal rebars. When CFS beams are designed to carry heavy loads, their depth logically increases, resulting in an increase in building floor height. The experimental and numerical investigation of CFS composite beams reinforced with diagonal web rebars is presented in this paper. A total of twelve built-up CFS beams were used for testing, with the first six designed without web encasement and the remaining six designed with web encasement. The first six were constructed with diagonal rebars in the shear and flexure zones, while the other two with diagonal rebars in the shear zone, and the last two without diagonal rebars. The next set of six beams was constructed in the same manner, but with a concrete encasement of the web, and all the beams were then tested. Fly ash, a pozzolanic waste byproduct of thermal power plants, was used as a 40% replacement for cement in making the test specimens. CFS beam failure characteristics, load-deflection behavior, ductility, load-strain relationship, moment-curvature relationship, and lateral stiffness were all investigated. The results of the experimental tests and the nonlinear finite element analysis performed in ANSYS software were found to be in good agreement. It was discovered that CFS beams with fly ash concrete encased webs have twice the moment resisting capacity of plain CFS beams, resulting in a reduction in building floor height. The results also confirmed that the composite CFS beams have high ductility, making them a reliable choice for earthquake-resistant structures.

text: Composite Cold-Formed Steel Beams with Diagonal Rebars for Earthquake-Resistant Buildings The construction industry is on the lookout for cost-effective structural members that are also environmentally friendly. Built-up cold-formed steel (CFS) sections with minimal thickness can be used to make beams at a lower cost. Plate buckling in CFS beams with thin webs can be avoided by using thick webs, adding stiffeners, or strengthening the web with diagonal rebars. When CFS beams are designed to carry heavy loads, their depth logically increases, resulting in an increase in building floor height. The experimental and numerical investigation of CFS composite beams reinforced with diagonal web rebars is presented in this paper. A total of twelve built-up CFS beams were used for testing, with the first six designed without web encasement and the remaining six designed with web encasement. The first six were constructed with diagonal rebars in the shear and flexure zones, while the other two with diagonal rebars in the shear zone, and the last two without diagonal rebars. The next set of six beams was constructed in the same manner, but with a concrete encasement of the web, and all the beams were then tested. Fly ash, a pozzolanic waste byproduct of thermal power plants, was used as a 40% replacement for cement in making the test specimens. CFS beam failure characteristics, load-deflection behavior, ductility, load-strain relationship, moment-curvature relationship, and lateral stiffness were all investigated. The results of the experimental tests and the nonlinear finite element analysis performed in ANSYS software were found to be in good agreement. It was discovered that CFS beams with fly ash concrete encased webs have twice the moment resisting capacity of plain CFS beams, resulting in a reduction in building floor height. The results also confirmed that the composite CFS beams have high ductility, making them a reliable choice for earthquake-resistant structures.

year: 2023-04-10

title: Do the urban poor face higher food prices? Evidence from Vietnam

authors: Gibson, John

subjects: food prices

abstract: Whether there is a poverty penalty, in terms of food prices, is unsettled in the literature after more than four decades of study. Unit values from household surveys suggest that prices vary with income while outlet surveys typically find food prices varying with store type but not with neighborhood income. Most outlet surveys are from rich countries, with just one spatially limited study from a developing country. In this paper we use especially collected food price data from metropolitan areas of Vietnam to test whether the urban poor face higher food prices. Food prices in low-income neighborhoods are 1% lower, on average, than in other neighborhoods. Unit values give a different answer to the question of whether the poor face higher prices and are not suited to answer such a question.

text: Do the urban poor face higher food prices? Evidence from Vietnam Whether there is a poverty penalty, in terms of food prices, is unsettled in the literature after more than four decades of study. Unit values from household surveys suggest that prices vary with income while outlet surveys typically find food prices varying with store type but not with neighborhood income. Most outlet surveys are from rich countries, with just one spatially limited study from a developing country. In this paper we use especially collected food price data from metropolitan areas of Vietnam to test whether the urban poor face higher food prices. Food prices in low-income neighborhoods are 1% lower, on average, than in other neighborhoods. Unit values give a different answer to the question of whether the poor face higher prices and are not suited to answer such a question.

year: 2013

title: Tukua Kia Rere! Maori Adult Students Succeeding at University

authors: Williams, Daphne Christina (Tina)

subjects: Maori students in higher education

abstract: A considerable amount of research has focussed on Māori underachievement in mainstream education. There is, however, much less research that celebrates Māori academic success. Even less has been written about the experiences of adult Māori students who return to study long after leaving school and go on to become academically successful in higher education. This study contributes to the growing body of knowledge regarding Māori academic success at university. It sought to explore the experiences of sixteen adult Māori students who entered university via special admission and went on to attain undergraduate degrees. The study examined the challenges that these individual’s experienced on their way to becoming academically successful and identified the main factors that helped them to achieve educational success. An overarching Kaupapa Māori theoretical framework was employed in this study. A qualitative research methodology was implemented and Kaupapa Māori research principles informed both the research processes and the interpretation of research outcomes. The findings suggest four major factors contributed to the success of the participants in this study: a strong determination to succeed (whāia te iti kahurangi), the extended family (whānau), strong social support networks with peers and faculty (whakawhanaungatanga) and Te Ao Māori (the Māori World). However, some of these same factors were also found to hinder academic success in the university setting. The Manu Tukutuku (kite) model was developed directly from the research findings. In addition to providing a theoretical frame for understanding the experiences of Māori special admission students at university, this model also provides a useful ‘toolkit’ for those wanting to support Māori students within the university context. The implications of this study suggest that New Zealand Universities can better support Māori special admission students by being more inclusive of their cultural capital, by eliminating racism and discrimination in the university environment and by fostering better relationships between staff and students. Creating opportunities for Māori students to develop social networks at University was also identified as important.

text: Tukua Kia Rere! Maori Adult Students Succeeding at University A considerable amount of research has focussed on Māori underachievement in mainstream education. There is, however, much less research that celebrates Māori academic success. Even less has been written about the experiences of adult Māori students who return to study long after leaving school and go on to become academically successful in higher education. This study contributes to the growing body of knowledge regarding Māori academic success at university. It sought to explore the experiences of sixteen adult Māori students who entered university via special admission and went on to attain undergraduate degrees. The study examined the challenges that these individual’s experienced on their way to becoming academically successful and identified the main factors that helped them to achieve educational success. An overarching Kaupapa Māori theoretical framework was employed in this study. A qualitative research methodology was implemented and Kaupapa Māori research principles informed both the research processes and the interpretation of research outcomes. The findings suggest four major factors contributed to the success of the participants in this study: a strong determination to succeed (whāia te iti kahurangi), the extended family (whānau), strong social support networks with peers and faculty (whakawhanaungatanga) and Te Ao Māori (the Māori World). However, some of these same factors were also found to hinder academic success in the university setting. The Manu Tukutuku (kite) model was developed directly from the research findings. In addition to providing a theoretical frame for understanding the experiences of Māori special admission students at university, this model also provides a useful ‘toolkit’ for those wanting to support Māori students within the university context. The implications of this study suggest that New Zealand Universities can better support Māori special admission students by being more inclusive of their cultural capital, by eliminating racism and discrimination in the university environment and by fostering better relationships between staff and students. Creating opportunities for Māori students to develop social networks at University was also identified as important.

year: 2010