Considering the permanent nature of the built environment, this dissertation investigates an alternative approach towards static architecture. Allowing the building’s users the ability to alter and determine their own environments due to ever evolving social needs. This architectural approach is thereafter metaphorically condensed to formulate a programme between isolation (prison) and freedom (society), where parolees are temporarily housed and given the opportunity to implement the production skills that were developed in prison. Allowing these parolees a second chance for redemption and the opportunity to ‘give back to society’ through the production process of recyclable waste into new sustainable products. The architectural concept should be understood in various different time scales over which the building changes, thus designing for disassembly by utilising a modular and kit-of-parts approach. / Dissertation (MArch(Prof))--University of Pretoria, 2011. / Architecture / unrestricted

As global solid waste management systems evolve to include wider elements of sustainability, developing countries are struggling with how best to work with a growing informal sector. This research seeks to investigate how developing country mainstream solid waste management systems can harness the opportunities presented through the informal recycling sector. This research explores the dialogue around „formalisation of the informal‟ and „integration of informal recycling sector into mainstream solid waste management systems‟, approaching this from an informal sector perspective. The research endeavours to offer insights to this discourse from an inclusive, social innovation approach. The research looks at what business models the informal recycling sector use as they adopt or adapt industrialised practices and how these harness inclusion and social innovation. The research area is Bulawayo, Zimbabwe with the informal recycling sector as case study. The main research question is “How can we harness inclusion and social innovation as the informal sector transitions into mainstream economic spaces?” The research employs an inductive qualitative approach through a rapid ethnography, focus group discussions and semi-structured key informant interviews. Key concepts explored in this research include „circumstantial social entrepreneurship‟, „generational informality‟, „value chain alliances‟, „public, private, community and informal sector partnerships (PPCIPs)‟ and „inclusive development as a pre-requisite to formalisation‟. By unpacking the business models employed by the informal recycling sector and how inclusive, social innovation opportunities inherent in these can be harnessed during the transition from shadow to mainstream economy spaces, this research intends to offer progressive approaches on how to unlock shared value during the graduation of the informal recycling sector from shadow to mainstream socio-economic spaces. Additionally, the outputs of this research aim to contribute to context-specific knowledge on types of non traditional social entrepreneurial activity within informal spaces and how these push boundaries of inclusive, social innovation.

In lakes, fish and zooplankton can be both sources and sinks of nitrogen (N) and phosphorus (P) through the consumption of organic N and P, and subsequent excretion of bioavailable inorganic forms. These source/sink dynamics, known as consumer-driven nutrient recycling (CNR), may, in turn, control the availability of potentially limiting nutrients for algal primary production. In this dissertation I investigate the importance and controls of CNR as a source of inorganic N and P for primary production (Chapter 2). I then examine zooplankton CNR as a mechanism for increasing nutrient mean resident time (MRT) in the mixed layer of lakes (Chapter 3). Finally, I assess whether zooplankton communities dominated by different taxa can affect N versus P deficient conditions for phytoplankton production through differential N and P recycling rates (Chapter 4). Direct excretion of N and P by fish communities was modest in arctic lakes, and accounted for < 4 % of the N and P required for primary production. Recycling of N and P by zooplankton communities was relatively high, and the fraction of algal N and P demand supplied by zooplankton CNR ranged from 4 - 90% for N and 7 - 107% for P. MRT of 15N, measured in the mixed layer of an arctic lake, was ~16 days, compared to 14 days predicted by a ecosystem model simulation with zooplankton N recycling and 8 days in a model simulation where zooplankton N recycling was absent. The 75% increase in N MRT between model simulations with and without zooplankton recycling suggests that zooplankton N recycling is an important mechanism for retaining N in lake ecosystems. I observed relatively high negative correlations between precipitation and phytoplankton N (r = -0.33) and P (r = -0.30) deficiencies. I also observed a significant positive correlation (r = 0.42, p = 0.03) between zooplankton communities with higher copepod biomass, relative to cladoceran biomass, and phytoplankton N-deficient conditions. These results suggest that when precipitation is high N and P deficiency is low in the phytoplankton. When precipitation is low, however, zooplankton communities composed primarily of copepods contribute to N-deficient conditions for phytoplankton production.

The interest of this work is found in the potential ways of reconstructing 2hand garments and how form and wear can be explored within that field. The methods applied on 2hand garments investigate traditional usage, shape and how to create new form and silhouettes, while allowing a reconstructed garment to be reversed/transformed back to original state. The aim is that the garments are to keep it’s original value, and thus making its sustainable potential higher. Significantly, the project discusses how our pre-existing visual perception of unwanted 2hand garments can be expanded, when they are reconstructed and recycled (unharmed).

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Reclaimed asphalt pavement (RAP) is a valuable resource that can be recycled into new asphalt mixtures. In recent years, the continued rise of raw material costs has generated considerable interest in increasing RAP usage. Warm mix asphalt (WMA) is a modern development in the asphalt industry that can potentially help increase RAP usage and achieve adequate mixture performance. The purpose of this dissertation is to: 1) develop a method to characterize the absorbed, inert and effective bituminous components in RAP; and 2) evaluate performance of high RAP-WMA mixtures for various pavement applications including airfield surfaces, highway surfaces and highway bases. A unique approach was taken to characterize RAP properties that coupled a dataset of 568 asphalt mix designs spanning five years of practice and testing 100% RAP with added virgin binder; 394 compacted specimens and 68 loose specimens were tested. A method to predict RAP absorbed asphalt was developed and shown to yield more reasonable results than conventional methods which were shown very likely to give incorrect absorbed asphalt contents in some conditions. The relative effectiveness of RAP surface asphalt was evaluated and estimates of inert and effective RAP asphalt were made for a variety of temperature, compactive effort, and warm mix additive conditions. Results showed different behaviors between RAP sources and between hot and warm mix temperatures. These results were also observed in volumetrics of high RAP mixtures. Performance evaluation was based on testing 75 slab specimens and more than 1100 gyratory specimens. Test data indicated a potential for decreased durability as RAP content increases; however 25% RAP highway surface mixtures and 50% RAP base mixtures had similar performance to current practice. Low temperature mixture stiffness testing and thermal cracking analysis indicated slightly increased stiffness with high RAP and 25% RAP highway surface mixtures that had comparable performance to current practice. Dry rut testing indicated high RAP mixtures are rut resistant. Moisture damage testing of high RAP mixtures indicated passing results in tensile strength ratio testing but potential for moisture damage in loaded wheel tracking. Overall, 25% RAP highway surface mixtures are recommended for immediate implementation.

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The scrap metal recycling industry is a growing industry that plays an important role in the sustainability of a large global metal supply. Unfortunately, recycling lacks many standards, and test procedures in place for mineral processing. These standards and practices, if used in recycling, could aid recyclers in determining and achieving optimal separations for their plant.. New regulations for scrap imports into China make it difficult to obtain the metal recoveries that have been achieved in the past. In order to help scrap yards adhere to the new regulations the Eriez RCS eddy current separator system was tested in full scale. The principles this system uses, called circuit analysis, have been used by the mining industry for years, and can be used with any separation system. The Eriez RCS system surpassed the requirements of the Chinese regulations, while simultaneously increasing the recovery of metals. In order to further analyze eddy current separator circuits, tree analysis was attempted for single eddy current separators, as well as more complex circuits mimicked using locked cycle tests. The circuits used in the locked cycle test were a rougher-cleaner, a rougher-scavenger, and a rougher-cleaner-scavenger. It was found that it is possible to use tree analysis to compare different eddy current separator circuits using the same settings, however standards for this practice need to be established for it to be useful. Using the data analysis methods developed for this particular tree analysis, the rougher-cleaner-scavenger test had the best performance overall. This is the same result as the full scale testing done on the Eriez RCS system, but more testing should be conducted to confirm the data analysis techniques of calculating theoretical efficiency, recovery efficiency, and rejection efficiency. / Master of Science

Pallets are the single largest consumer of hardwood lumber in the United States. While the pallet industry has effectively adopted widespread pallet recycling, many pallets still go into landfills with little or no value gained from their material. Recovered pallet lumber has been proposed as a potential source of material for value added wood products. This study sought preliminary data on issues pertinent to the development of pallet parts as a source of raw material for value added products, with a focus on oak strip flooring. Issues examined included pallet disassembly efficiency, characteristics of recovered boards, and yield of blanks compatible with commercial flooring production. Disassembly of pallets was affected by pallet design. Overall 81% of the deckboards from all pallet designs were recovered, along with 70% of stringers. Oak boards useable in strip flooring represented 21% of the recovered boards studied. Proper board stacking was found to maintain a uniform (MC) which would reduce drying defects and complications. The manufactured blank dimensions would allow production of some of the thinner strip flooring commercially available. National Oak Flooring Manufacturers Association Pre-finished Oak Strip Flooring Grading Rules found almost 80% of the blanks made Prime and Standard Grades. Wide spread adoption of flooring production from recovered pallet would increase the value of recovered pallets, presumably justifying an increased rate and expanded scope of pallet recovery. Economics favoring such valued added recovery would create recovery-related jobs, decrease pallets going into landfills, and ease the demand on timber resources. / Master of Science