Unbound granular material is used in the pavement structure and usually comprises the bulk of the structural and foundation layers of a typical South African pavement. The term ‘unbound granular material’ refers to the classification of natural material, which has not been modified in any way. Various mechanistic-empirical models for the resilient response of unbound granular material have been developed over the years. However, few have incorporated important influencing parameters such as moisture or density on the basic stress-strain relationship or linked variables of the models to basic engineering properties of unbound granular material. This study builds on previous work by Theyse (2008a) and the cord modulus model developed by Theyse (2012). The Theyse (2012) model was selected to be further investigated, since it modelled the trends observed in the data realistically. The model depicts the stress dependent behaviour of unbound granular material, where an increase initial modulus is observed for increasing confinement pressure, as well as initial stress-softening with increasing stress ratio followed by stress stiffening. The model was calibrated for all bulk material samples under consideration in this thesis. The calibration process included linking variables of the model to mathematical functions that approximate the trends observed when variables were considered against level of saturation. A parametric analysis indicated that the saturation and stress-dependent cord modulus model realistically predict material behaviour. The saturation and stress-dependent cord modulus model was refined further and calibrated for crushed and natural unbound granular material. This refinement did not negatively influence the accuracy or ability to realistically predict the material behaviour. Basic material properties could be linked to predictive statistical distributions that could estimate the range of modulus values that can be expected for the material under consideration. However, the variables of the saturation and stress-dependent cord modulus model could not be linked to basic material properties due to the limit set of results available. / Thesis (PhD)--University of Pretoria, 2013. / gm2013 / Civil Engineering / unrestricted

Seeing beauty in the simplest aspects of nature inspires me to create art as a testament to our world. Being raised on a farm in rural Virginia gave me an appreciation of a reverence for all life. The inherent forms along with color and value establish nature as the master of aesthetics. An early introduction to Japanese art showed me that all nature was worthy and significant as subjects for art. Using materials derived from nature, cotton, linen, wool, silk, adds a tactile quality that I believe elevates the enjoyment of art.

Chromium and other heavy metals are known to cause issues related to human and environmental health when they occur in high concentrations in ecosystems. Chromium poses a particularly large threat if it occurs in its hexavalent form, Cr(VI), as it is highly reactive and carcinogenic. The aim of this project was to investigate the wastewater emitted from a tannery in Liwonde, Malawi, with respect to the metals Cr, Al, Cd, Cu, Fe, Mn, Pb and Zn, and to reduce the concentrations using locally available materials. A particular emphasis was put on chromium.   Wastewater collected from the tannery was analysed to determine the total and dissolved concentrations of the metals using a Microwave Plasma-Atomic Emission Spectrometer (MP-AES). The wastewater was then mixed with various dosages of peeled and unpeeled Moringa Oleifera seed powder as well as pure Moringa Oleifera shell powder and sand collected from river Shire. Thereafter, the remaining concentrations of metals were analysed. Additional analyses of various contact times were performed for the removal agent that had shown the best results.     The analyses showed a total chromium concentration of 2.25 ppm and a dissolved chromium concentration of 0.251 ppm in the wastewater discharged from the tannery. Both concentrations were lower than what had initially been expected but still above both the WHO guideline value for chromium in drinking water and the Swedish threshold value for chromium in industrial wastewater (0.05 ppm). No other metals were found in concentrations above trace levels. All of the investigated removal agents, except for pure shell powder, showed positive results for chromium removal. The highest removal observed for dissolved chromium was 72 % and occurred with a removal agent mixture of 5.0 g of river sand and 2.0 g of unpeeled Moringa Oleifera seed powder to 100 mL of wastewater. The reduction of total chromium was 97 % for the same removal agent mixture. However, lower dosages of the removal agents also gave a chromium removal of similar size. Due to resource limitations, no analysis of whether the wastewater contained Cr(III) and Cr(VI) could be performed.   Considering the low initial concentrations of metals emitted from the tannery, there is no urgent need for further treatment of the wastewater. This study has however substantiated the theory that Moringa Oleifera seeds can be used as a low-cost chromium remediation agent in wastewater, a result that can be of use to improve the water quality in other industries and applications. / Det har länge varit känt att krom och andra tungmetaller kan orsaka hälso- och miljöproblem när de förekommer i höga koncentrationer i ekosystem. Krom utgör ett särskilt stort hot om det förekommer i sin sexvärda form, Cr(VI), eftersom det är mycket reaktivt och cancerogent. Syftet med detta projekt var att undersöka avloppsvattnet från ett garveri i Liwonde, Malawi, med avseende på metallerna Cr, Al, Cd, Cu, Fe, Mn, Pb och Zn, samt att minska koncentrationerna med hjälp av lokalt tillgängliga material. En särskilt tonvikt lades på krom.   Avloppsvatten som inhämtats från garveriet analyserades med hjälp av en mikrovågsplasma-atomemissionsspektrometer (MP-AES) för bestämning av total samt löst koncentration av metallerna. Avloppsvattnet blandades sedan med olika doser av pulver från skalade och oskalade Moringa Oleifera-frön, liksom med pulver från skal av Moringa Oleifera-frön och sand från Shire-floden. Därefter analyserades proverna med avseende på återstående metallkoncentrationer. Ytterligare undersökningar genomfördes med olika kontakttider för det inbindningsmedel som visat bäst resultat.   Analyserna visade en total kromkoncentration på 2,25 ppm och en löst kromkoncentration på 0,251 ppm i det avloppsvatten som släpptes ut från garveriet. Båda koncentrationerna var lägre än vad som ursprungligen hade förväntats, men ändå över både WHOs riktlinjer för krom i dricksvatten och det svenska gränsvärdet för krom i industriellt avloppsvatten (0,05 ppm). Inga andra metaller påvisades i betydande koncentrationer. Alla undersökta inbindningsmedel, med undantag av Moringa Oleifera-skal, visade positiva resultat för kromrening. Den största observerade reningen för löst krom var  72 %, och uppmättes för en blandning av 5,0 g sand och 2,0 g pulver av oskalade Moringa Oleifera-frön till 100 mL avloppsvatten. Reduktionen av totalt krom var 97 % för samma blandning. Även lägre doser gav dock en nästan lika hög reningsgrad. På grund av resursbegränsningar kunde ingen analys av huruvida avloppsvattnet innehöll Cr(III) eller Cr(VI) genomföras.   Då avloppsvattnet från garveriet endast innehöll låga koncentrationer av metaller finns inget akut behov av ytterligare rening. Denna studie har dock styrkt tesen att Moringa Oleifera-frön kan användas som ett lågkostnadsalternativ för rening av krom i avloppsvatten. Detta resultat kan vara användbart för att förbättra vattenkvaliteten vid andra industrier och tillämpningar.

The theoretical part of the thesis is concerned with topics related to project teaching,creativity,framework educational program in field of Man and the world of work and property of nature. The practical part consists of 11 project using products of nature. The end of the practical part deals with verification of created projects and evaluation of implemented projects.

Large amount of different types of industrial wastes are still not re-use as secondary raw materials in industry. The work deals with finding a new way how to use secondary raw materials, especially the possibilities of using recycled glass from different sources as a fillers in the polymer protective materials development for horizontal structures. The main task of this work is to develop a material with the desired physic - mechanical properties and further verifying the influence of particle shape on their chemical resistance. Result of this work will find advanced protective materials using secondary raw materials as alternatives to be in terms of economic and ecological efficiency replacement for conventional products.

The aim of the thesis is to create a landscape that supports water retention and helps the river Dyje to create a branched, meandering watercourse. The design also deals with the permeability of the territory and the design of wooden objects that respond in function and shape to the created landscape.

[pt] A tese investiga os princípios da pesquisa experimental para a criação de objetos em harmonia com o meio ambiente físico e social. A base para este estudo é a pesquisa realizada no Laboratório de Investigação em Livre Desenho (LILD) da PUC-Rio. Defendemos a tese de que a metodologia experimental para a pesquisa dessas técnicas se beneficia tanto de elementos da cultural material pré-industrial, quanto de técnicas informatizadas e do conhecimento universitário moderno. A partir do encontro desses diferentes saberes, a pesquisa experimental pode enriquecer seus parâmetros e ter maior potencial para a geração de objetos em harmonia com o meio ambiente físico e social. A tese conta com o resultado da pesquisa em dois campos - uma aldeia indígena na Amazônia e o laboratório CPI (Construction Process Investigation), da Universidade do Havaí. Também é feita a descrição de oficinas realizadas para o compartilhamento de técnicas desenvolvidas no laboratório. A partir dos elementos, apresentamos um debate acerca da pesquisa e do desenvolvimento de objetos em harmonia com o meio ambiente físico e social e concluímos que o encontro entre os conhecimentos da cultura material de sociedades pré-industriais e da pesquisa acadêmica ligada à indústria potencializa a metodologia da pesquisa de técnicas em harmonia com o meio ambiente físico e social. / [en] This thesis investigates the principles of the experimental research for the creation of objects that are in harmony with the physical and social environments. The base for this study is the research done in the Laboratório de Investigação em Livre Desenho (LILD). We defend the idea that the experimental methodology in this kind of research is enrichened both by elements of pre-industrial material culture and by modern academic knowledge. With these different knowledges, experimental research can enrich its parameters and have greater potential to create objects in harmony with the physical and social environments. Thus, the thesis has the result of two fiel researches - and indigenous village in the Amazon and the CPI (Construction Process Innovation) lab of the University of Hawaii. There is also a description of workshops that have been done to share the techniques developed in the laboratory. Based on these elements, we present a discussion about the experimental research and about the development of objects in harmony with the physical and social environments, and we come to the conclusion that the integration of elements of pre-industrial societies and of academic research related to the industry favors to the development of the methodology for research of techniques in harmony with the physical and social environments.