Influence of mix proprtions on rheolgy of cement grouts containing limestone powder

In this paper the parameters of cement grout affecting rheological behaviour and compressive strength are investigated. Factorial experimental design was adopted in this investigation to assess the combined effects of the following factors on fluidity, rheological properties, induced bleeding and compressive strength: water/binder ratio (W/B), dosage of superplasticiser (SP), dosage of viscosity agent (VA), and proportion of limestone powder as replacement of cement (LSP). Mini-slump test, Marsh cone, Lombardi plate cohesion meter, induced bleeding test, coaxial rotating cylinder viscometer were used to evaluate the rheology of the cement grout and the compressive strengths at 7 and 28 days were measured. A two-level fractional factorial statistical model was used to model the influence of key parameters on properties affecting the fluidity, the rheology and compressive strength. The models are valid for mixes with 0.35-0.42 W/B, 0.3-1.2% SP, 0.02-0.7% VA (percentage of binder) and 12-45% LSP as replacement of cement. The influences of W/B, SP, VA and LSP were characterised and analysed using polynomial regression which can identify the primary factors and their interactions on the measured properties. Mathematical polynomials were developed for mini-slump, plate cohesion meter, inducing bleeding, yield value, plastic viscosity and compressive strength as function of W/B, SP, VA and proportion of LSP. The statistical approach used highlighted the limestone powder effect and the dosage of SP and VA on the various rheological characteristics of cement grout

Critical Dialogue in Architecture Studio: Peer Interaction and Feedback

Most tutors in architecture education regard studio-based learning to be rich in feedback due to is dialogic nature. Yet, student perceptions communicated via audits such as the UK National Student Survey appear to contradict this assumption and challenge the efficacy of design studio as a truly discursive learning setting. This paper presents findings from a collaborative study that was undertaken by the Robert Gordon University, Aberdeen, and Queen’s University Belfast that develop a deeper understanding of the role that peer interaction and dialogue plays within feedback processes, and the value that students attribute to these within the overall learning experience.

The paper adopts a broad definition of feedback, with emphasis on formative processes, and including the various kinds of dialogue that typify studio-based learning, and which constitute forms of guidance, direction, and reflection. The study adopted an ethnographic approach, gathering data on student and staff perceptions over the course of an academic year, and utilising methods embracing both quantitative and qualitative data.

The study found that the informal, socially-based peer interaction that characterises the studio is complementary to, and quite distinct from, the learning derived through tutor interaction. The findings also articulate the respective properties of informal and formally derived feedback and the contribution each makes to the quality of studio-based learning. It also identifies limitations in the use or value of peer learning, understanding of which is valuable to enhancing studio learning in architecture.

Understanding Student and Staff Perceptions of Feedback in Architecture: Summary Report

This report presents the results of a collaborative project between Queens University, Belfast and the Robert Gordon University, Aberdeen, and builds on a dialogue initiated during Session 2009-10 through which course guidance and feedback received by students was identified as an area requiring deeper understanding in order to enhance current practice

Revisiting Iris Marion Young on Normalisation, Inclusion and Democracy

Vieten's edited collection brings together papers that were given at the I M Young Memorial Symposium 'Inclusion and Democracy Revisited', held in Amsterdam in 2012. The different chapters presented explore in-depth, Young's models of a 'politics of cultural difference', and a 'politics of positional difference' read in combination with her critique of normalisation. Young regards the latter as decisive to any change for the better when reaching out politically to a fairer and more just democratic society.
With the current political, economic and socio-cultural crisis in mind, the contemporary world of global speed and transformed societies in and beyond Europe needs a refinement of what we understand 'normalisation' and 'difference' to be. How can we connect to each other, and in what ways can Young's 'structural inequality model' be applied to develop alternative outlooks on how to enhance inclusion and democracy in different nation states?

Transcending epithelial and intracellular biological barriers; a prototype DNA delivery device

Microneedle technology provides the opportunity for the delivery of DNA therapeutics by a non-invasive, patient acceptable route. To deliver DNA successfully requires consideration of both extra and intracellular biological barriers. In this study we present a novel two tier platform; i) a peptide delivery system, termed RALA, that is able to wrap the DNA into nanoparticles, protect the DNA from degradation, enter cells, disrupt endosomes and deliver the DNA to the nucleus of cells ii) a microneedle (MN) patch that will house the nanoparticles within the polymer matrix, breach the skin's stratum corneum barrier and dissolve upon contact with skin interstitial fluid thus releasing the nanoparticles into the skin. Our data demonstrates that the RALA is essential for preventing DNA degradation within the poly(vinylpyrrolidone) (PVP) polymer matrix. In fact the RALA/DNA nanoparticles (NPs) retained functionality when in the MN arrays after 28days and over a range of temperatures. Furthermore the physical strength and structure of the MNs was not compromised when loaded with the NPs. Finally we demonstrated the effectiveness of our MN-NP platform in vitro and in vivo, with systemic gene expression in highly vascularised regions. Taken together this 'smart-system' technology could be applied to a wide range of genetic therapies.