Construction and demolition waste management : assessment of demand and supply of recycled materials in the Western Cape

Includes bibliographical references (leaves 96-100).Concern for environmental degradation has been a motivating factor in the efforts to reuse or recycle construction and demolition waste. The intention is not only to reduce environmental desecration, but also to recycle the construction and demolition waste into potential building materials to be reused elsewhere. This study investigated the supply and demand of recycled construction materials in the Western Cape, and aimed to determine the perception held by important stakeholders about these materials. A qualitative analysis of the case study results revealed that poor waste management plans implemented on construction and demolition sites have affected the quality, supply and price of recycled materials. In addition to this it was also revealed that the negative perceptions regarding recycled materials were the major barriers to creating an established secondary market. Inadequate knowledge and experience were major contributors to resistance to change of perceptions. A case study was conducted on Malans Quarries Recyclers in order to determine the supply of raw materials (construction and demolition waste) reaching the recycling plant; the supply of recycled materials to the end user (consumer); and the recycling process that takes place. A sample of fifteen respondents from a variety of large, medium and small construction contractors, as well as consultants and civil engineering companies, completed a questionnaire to determine the demand for and perceptions about these materials. The qualitative analysis of the results of the questionnaires showed that the majority of respondents still preferred to use primary materials over recycled materials. However, it appears that the gap between respondents who prefer to use primary materials, and those who utilize recycled materials, has narrowed in comparison to results obtained in previous studies. It seems that there may be more usage of recycled materials in the future. The results also revealed that tax cuts, could be a good economic incentive to encourage the use of recycled material. The questionnaire results also revealed that the majority of the respondents believed that landfill taxes where not effective in discouraging the illegal dumping of waste, and that the lack advertisements, and difficulties in obtaining recycled materials played a crucial role in the under-use of recycled materials

Designing for Mixed Reality Urban Exploration

This paper introduces a design framework for mixed reality urban exploration (MRUE), based on a concrete implementation in a historical city. The framework integrates different modalities, such as virtual reality (VR), augmented reality (AR), and haptics-audio interfaces, as well as advanced features such as personalized recommendations, social exploration, and itinerary management. It permits to address a number of concerns regarding information overload, safety, and quality of the experience, which are not sufficiently tackled in traditional non-integrated approaches. This study presents an integrated mobile platform built on top of this framework and reflects on the lessons learned

Influence of enzyme immobilization and skin-sensor interface on non-invasive glucose determination from interstitial fluid obtained by magnetohydrodynamic extraction

We integrated a magnetohydrodynamic fluid extractor with an amperometric glucose biosensor to develop a wearable device for non-invasive glucose monitoring. Reproducible fluid extraction through the skin and efficient transport of the extracted fluid to the biosensor surface are prerequisites for non-invasive glucose monitoring. We optimized the enzyme immobilization and the interface layer between the sensing device and the skin. The monitoring device was evaluated by extracting fluid through porcine skin followed by glucose detection at the biosensor. The biosensor featured a screen-printed layer of Prussian Blue that was coated with a layer containing glucose oxidase. Both physical entrapment of glucose oxidase in chitosan and tethering of glucose oxidase to electrospun nanofibers were evaluated. Binding of glucose oxidase to nanofibers under mild conditions provided a stable biosensor with analytical performance suitable for accurate detection of micromolar concentrations of glucose. Hydrogels of varying thickness (95-2000 mu m) as well as a thin (30 mu m) nanofibrous polycaprolactone mat were studied as an interface layer between the biosensor and the skin. The effect of mass transfer phenomena at the biosensor-skin interface on the analytical performance of the biosensor was evaluated. The sensing device detected glucose extracted through porcine skin with an apparent (overall) sensitivity of-0.8 mA/(M.cm(2)), compared to a sensitivity of-17 mA/(M.cm(2)) for measurement in solution. The amperometric response of the biosensor correlated with the glucose concentration in the fluid that had been extracted through porcine skin with the magnetohydrodynamic technique.Peer reviewe

Sampling of fluid through skin with magnetohydrodynamics for noninvasive glucose monitoring

Out of 463 million people currently with diabetes, 232 million remain undiagnosed. Diabetes is a threat to human health, which could be mitigated via continuous self-monitoring of glucose. In addition to blood, interstitial fluid is considered to be a representative sample for glucose monitoring, which makes it highly attractive for wearable on-body sensing. However, new technologies are needed for efficient and noninvasive sampling of interstitial fluid through the skin. In this report, we introduce the use of Lorentz force and magnetohydrodynamics to noninvasively extract dermal interstitial fluid. Using porcine skin as an ex-vivo model, we demonstrate that the extraction rate of magnetohydrodynamics is superior to that of reverse iontophoresis. This work seeks to provide a safe, effective, and noninvasive sampling method to unlock the potential of wearable sensors in needle-free continuous glucose monitoring devices that can benefit people living with diabetes.Peer reviewe

Pilot study in human healthy volunteers on the use of magnetohydrodynamics in needle-free continuous glucose monitoring

The benefits of continuous glucose monitoring (CGM) in diabetes management are extensively documented. Yet, the broader adoption of CGM systems is limited by their cost and invasiveness. Current CGM devices, requiring implantation or the use of hypodermic needles, fail to offer a convenient solution. We have demonstrated that magnetohydrodynamics (MHD) is effective at extracting dermal interstitial fluid (ISF) containing glucose, without the use of needles. Here we present the first study of ISF sampling with MHD for glucose monitoring in humans. We conducted 10 glucose tolerance tests on 5 healthy volunteers and obtained a significant correlation between the concentration of glucose in ISF samples extracted with MHD and capillary blood glucose samples. Upon calibration and time lag removal, the data indicate a Mean Absolute Relative Difference (MARD) of 12.9% and Precision Absolute Relative Difference of 13.1%. In view of these results, we discuss the potential value and limitations of MHD in needle-free glucose monitoring.Peer reviewe

Early Disease Activity or Clinical Response as Predictors of Long-Term Outcomes With Certolizumab Pegol in Axial Spondyloarthritis or Psoriatic Arthritis

Pathophysiology and treatment of rheumatic disease

NEW LIGHT-WEIGHT STEREOSOPIC SPECTROMETRIC AIRBORNE IMAGING TECHNOLOGY FOR HIGH-RESOLUTION ENVIRONMENTAL REMOTE SENSING – CASE STUDIES IN WATER QUALITY MAPPING

A new Fabry-Perot interferometer (FPI) based light-weight spectrometric camera provides new possibilities for environmental remote sensing applications. The sensor collects spectral data cubes with adjustable spectral properties in a rectangular image format, and so stereoscopic data can be obtained by gathering images in block structures with overlapping images. The FPI camera thus enables stereoscopic, spectrometric remote sensing applications with light-weight, low-cost airborne imaging systems. Our objective is to investigate the processing and use of this new imaging technology in a water quality mapping. We carried out imaging campaigns over a small lake in summer and autumn 2012 using a light-weight unmanned airborne vehicle (UAV) and a small manned airborne vehicle (MAV). We present the preliminary results of these campaigns

A comparison of methods for purification and concentration of norovirus GII-4 capsid virus-like particles

Noroviruses (NoVs) are one of the leading causes of acute gastroenteritis worldwide. NoV GII-4 VP1 protein was expressed in a recombinant baculovirus system using Sf9 insect cells. Several methods for purification and concentration of virus-like particles (VLPs) were evaluated. Electron microscopy (EM) and histo-blood group antigen (HBGA) binding assays showed that repeated sucrose gradient purification followed by ultrafiltration resulted in intact VLPs with excellent binding to H type 3 antigens. VLPs were stable for at least 12 months at 4°C, and up to 7 days at ambient temperature. These findings indicate that this method yielded stable and high-quality VLPs