Constructing (Dis)ability through participation in early childhood markets: Preschool leaders’ enrolment decision-making

This article employs a critical case study (critical disability studies and critical policy analysis) to unpack how leaders in publicly funded private prekindergarten programs invoke conceptions of normality, and subsequently abnormality, during decision-making processes for student (dis)enrolment. More specifically, this research is concerned with ways private preschool leaders’ constructions of disability are implicated in decision-making affecting student enrolment and disenrollment, thereby facilitating constructions of children’s participation in this state-sanctioned early childhood education program. Three leadership teams at private preschools participated in responsive interviews, observations, and provided policy and curricular documents for analysis. Findings reveal how policy, market, and preschool leaders’ conceptions of (ab)normality influenced decision-making rationales and outcomes affecting (dis)enrolled students. Additionally, findings indicated leaders’ sense of identity impacted their interpretation of and reaction to program polices, local market pressures, and their construction of the “good consumer”—a parent/child dyad prepared for rigor with the exhibition of self-control. This research evinces complexities undergirding leaders’ decision-making when choosing to (dis)enrol students in publicly-funded voucher programs on privately-driven markets and how decisions function to (re)shape (dis)ability discourses in early childhood

The increasing numbers of vacant houses, fuelled by thehousing crisis, are associated with higher burglary rates

One of the more visible aspects of the Great Recession and its associated housing crisis has been the rise in the number of vacant homes across the U.S. But has this increase in the number of empty houses had an effect on other social problems such as crime? In new research that uses Census data on home vacancies, and FBI data on crime, Roderick W. Jones and William Alex Pridemore find that when a city’s home vacancy rate increased by one percent, its burglary rate rose by 1.21 percent, but that its robbery rate remained unchanged. They also find that the local unemployment rate is important to this relationship, with higher rates associated with diminished crime rates

Modelling the ability of legumes to suppress weeds

The ability of different legume cover crops to suppress annual weeds during the early establishment phase was compared using a simulation model of inter-plant competition and field observations. Height, partitioning parameters, extinction coefficients, crop density and time of emergence were recorded for 11 species sown in monocultures. A naturally occurring population of fat hen (Chenopodium album) was present on the experiment. The competition model was run to compare the expected suppressive ability of the different species on this weed. Samples of C. album were also taken from each plot immediately prior to cutting to provide some empirical observations. Predicted suppressive ability was correlated with seed size and height with large seeded, tall species such as white sweet clover being the most competitive. However, these species may recover poorly from mowing compromising their potential to suppress perennial weeds and a mixture of contrasting species may provide the optimum weed control

Performance of a multi-layer aligned steel fibre reinforced concrete beam:A preliminary investigation towards 3D printing

Fibre alignment and 3D concrete printing have become increasingly popular in research and industry while these technologies face a lack of deep integration. Aligning steel fibres in concrete is different from in mortar systems due to the interference originated from coarse aggregate. This paper reports the results of an experimental programme investigating manufacturing reinforced concrete by placing concrete and aligned steel fibres in multi-layer in replicating the 3D printing. The X-ray CT scan was deployed to characterise the fibre distribution by digitally colouring the fibre orientation deviation and calculating the fibre orientation efficiency which reached 0.77 in this study. 4-point bending tests were performed on beam specimens of the multi-layer aligned steel fibre reinforced concrete to assess the flexural performance. Alignment of the steel fibres resulted in 56% increase of the ultimate load resistance compared to that being two-dimensionally distributed. A model for estimating the tensile strength of multi-layer aligned steel fibre reinforced concrete was developed with consideration of the layer proximity to the neutral axis of the beam. Change of the concrete composition was observed to yield influences on the interface bond performance between the fibre layer and concrete and the influences were quantified by correlating experimental data. This study revealed that the space characteristics of the fibre distribution in multi-layer required concrete mix constituent of good rheology to develop adequate bond performance for further additive manufacturing without formwork

Performance of a multi-layer aligned steel fibre reinforced concrete beam:A preliminary investigation towards 3D printing

Fibre alignment and 3D concrete printing have become increasingly popular in research and industry while these technologies face a lack of deep integration. Aligning steel fibres in concrete is different from in mortar systems due to the interference originated from coarse aggregate. This paper reports the results of an experimental programme investigating manufacturing reinforced concrete by placing concrete and aligned steel fibres in multi-layer in replicating the 3D printing. The X-ray CT scan was deployed to characterise the fibre distribution by digitally colouring the fibre orientation deviation and calculating the fibre orientation efficiency which reached 0.77 in this study. 4-point bending tests were performed on beam specimens of the multi-layer aligned steel fibre reinforced concrete to assess the flexural performance. Alignment of the steel fibres resulted in 56% increase of the ultimate load resistance compared to that being two-dimensionally distributed. A model for estimating the tensile strength of multi-layer aligned steel fibre reinforced concrete was developed with consideration of the layer proximity to the neutral axis of the beam. Change of the concrete composition was observed to yield influences on the interface bond performance between the fibre layer and concrete and the influences were quantified by correlating experimental data. This study revealed that the space characteristics of the fibre distribution in multi-layer required concrete mix constituent of good rheology to develop adequate bond performance for further additive manufacturing without formwork

High-volume, ultra-low-density fly ash foamed concrete

Resource efficiency is a core criterion for the regulation of construction products and rightly promotes the most sustainable solution. This paper reports the development a low embodied carbon dioxide backfill material based on an ultra-low-density foamed concrete using a high volume of fly ash to replace Portland cement. This material builds on previously reported research on the underlying causes of instability in low-density foamed concrete mixes and demonstrates that, with the addition of a small amount of calcium sulfoaluminate cement, stable ultra-low-density foamed concretes with density as low as 150 kg/m3 can be produced. A high volume of fly ash up to 70% of cement phase has been used, which reduced the average bubble size of the foamed concrete and increased the thickness of the bubble walls. The observed microstructure of fly ash foamed concretes was improved over the long term. The use of fly ash significantly reduced the embodied carbon dioxide of these mixes, which potentially has significant benefits for large-scale backfill and similar applications. </jats:p

Stability and instability of foamed concrete

Foamed concrete has proven to be an effective alternative to granular fills and is now widely used internationally. With increasing demand for lightweight materials for buildings in order to improve sustainability, foamed concrete has also developed as an ideal material for this purpose, and many countries utilise construction with precast foamed concrete blocks. However, at densities lower than current technology allows, typically &lt;500 kg/m3, foamed concretes are more prone to instability of the fresh mix. Furthermore at very low densities, ≤300 kg/m3, instability is almost inevitable, greatly limiting the potential of foamed concrete for applications where mass is critical (e.g. weak soils, backfilling damaged structure etc.). This paper aims to illustrate the mechanisms of stability and instability in foamed concretes and demonstrates how ultra-low density mixes (down to plastic density of 150 kg/m3) can be successfully produced. </jats:p