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Thesis ((MEng)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: When constructing a submarine pipeline, construction teams must work in the hostile environment in the ocean known as the surf zone. The surf zone is the area along a shoreline stretching between the first evident point of wave breaking and the beach line. In order to ensure that the pipeline is shielded from the imposing forces within the surf zone, engineers use a burial technique which leaves the pipeline length in the surf zone buried underneath the active seabed once construction is finished. Thus a temporary surf zone trench is dredged and protected by an open-ended cofferdam built using iron sheet piles. As a result of the incoming wave climate and the surf zone currents created by this wave climate, sedimentation in and around the trench becomes problematic. In this study alternative geometric layouts for the open-ended cofferdam protecting the surf zone trench are investigated, attempting to minimize the sediment build-up in and around the trench. This was done by using both a 3D qualitative physical model conducted at the CSIR in Stellenbosch, and numerical model using MIKE developed by DHI. However, this study only considers sediment build-up and not structural integrity and constructability of the cofferdam designs. Combining the observations of both the physical- and numerical models, a conclusion was drawn that a structure built perpendicular to the shoreline with a 45oextended arm built from the upstream edge of the cofferdam wall, is the most effective. No dimensions are given as the cofferdam design will change depending on the site specific characteristics. Also an increase in structure length will result in the mouth of the structure being located outside the active sediment zone, which leads to a longer period of time before the pipeline pathway is compromised by sediment. / AFRIKAANSE OPSOMMING: Tydens die konstruksie van 'n onderwaterse pyplyn, moet konstruksie spanne in 'n gevaarlike gedeelte van die see werk naamlik die brandersone. Die brandersone kan gedefinieer word as die area tussen die eerste punt waar branders breek en die strandlyn. Om die pyplyn te beskerm teen die kragte wat branders op dit uitoefen, gebruik ingenieurs 'n installasietegniek waar hul die brandersone seksie van die pyplyn onder die aktiewe seebodem begrawe. Om die tegniek te bewerkstellig, grawe kontrakteurs 'n sloot deur die brandersone en beskerm dit met 'n tydelike struktuur bekend as 'n kofferdam. As gevolg van die inkomende branders en die strome wat deur die branders aangedryf word, kan die opbou van sediment in, en rondom die sloot in die brandersone problematies word. Hierdie studie ondersoek alternatiewe uitlegte vir die tydelike kofferdam struktuur met die oog daarop om die opbou van sediment in, en rondom die struktuur te verminder. Die doel was nagestreef deur gebruik te maak van beide 'n 3-dimensionele fisiese model, gebou en gebruik by die WNNR in Stellenbosch, en 'n numeriese model wat op MIKE, ontwikkel deur DHI gedoen was. Let wel die studie het slegs die sediment beweging in die nabye area van die tydelike kofferdam struktuur in ag geneem en nie die praktiese implimentering en strukturele integriteit van die struktuur nie. Deur die observasies van beide die fisiese- en numeriese modelering in ag te neem, is die volgende gevolgtrekkings gemaak. 'n Struktuur wat loodreg met die strandlyn gebou is en met 'n 45o arm wat na die stroom-op kant toe uitstrek, was die mees effektiewe een. Geen dimensies is deurgegee nie aangesien die ontwerp sal verskil afhangende van die spesifieke area waar die projek aangepak word. Daar is ook gesien dat indien die struktuur langer gemaak word, sal die kontrakteur langer tyd h^e voordat daar sediment probleme in die brander sone sloot ondervind sal word.

Magister Chirurgiae Dentium - MChD (Prosthodontics) / The aim of this study was to evaluate and compare the physical properties of two core build-up materials (ParaCore and CoreXflow) and compare this to conventional composite material (Filtek Supreme Plus and SDR Flow) used as core build-up material.

The research described in the thesis details the investigation of build-up and wash-off process kinetics of Polycyclic Aromatic Hydrocarbons (PAHs) and heavy metals in urban areas. It also discusses the design and development of a rainfall simulator as an important research tool to ensure homogeneity and reduce the large number of variables that are usually inherent to urban water quality research. The rainfall simulator was used to collect runoff samples from three study areas, each with different land uses. The study areas consisted of sites with typical residential, industrial and commercial characteristics in the region. Build-up and wash-off samples were collected at each of the three sites. The collected samples were analysed for a number of chemical and physico-chemical parameters. In addition to this, eight heavy metal elements and 16 priority listed PAHs were analysed in five different particle size fractions of the build-up and wash-off samples. The data generated from the testing of the samples were evaluated using multivariate analysis, which reduced the complexity involved in determining the relative importance of a single parameter in urban water quality. Consequently, variables and processes influencing loadings and concentrations of PAHs and heavy metals in urban stormwater runoff from paved surfaces at any given time were identified and quantified using Principal Component Analysis (PCA). Furthermore, the process kinetics found were validated using a multivariate modelling approach and Partial Least Square (PLS) regression, which confirmed the transferability of chemical processes in urban water quality. Fine particles were dominant in both the build-up and wash-off samples from the three sites. This was mirrored in the heavy metal and PAH concentrations at the three sites, which were significantly higher in particles between 0.45-75μm than in any other fraction. Thus, the larger surface area and electrostatic charge of fine particles were favourable in sorbing PAHs and heavy metals. However, factors such as soil composition, total organic carbon (TOC), the presence of Fe and Mn-oxides and pH of the stormwater were all found to be important in partitioning of the metals and PAHs into different fractions. Additionally, PAHs were consistently found in concentrations above their aqueous solubility, which was attributed to colloidal organic particles being able to increase the dissolved fraction of PAHs. Hence, chemical and physico-chemical parameters played a significant role in the distribution of PAHs and heavy metals in urban stormwater. More importantly, the research showed the wide range of factors that distribute metals and PAHs in an urban environment. Furthermore, it indicated the need for monitoring these parameters in urban areas to ensure that urban stormwater management measures are effective in improving water quality. The build-up and wash-off process kinetics identified using PCA at the respective land uses were predicted using PLS and it was found that the transferability of the governing processes were high even though the PAHs and metal concentrations and loads were highly influenced by the source strength at each site. The increased transferability of fundamental concepts in urban water quality could have significant implications in urban stormwater management. This is primarily attributed to common urban water quality mitigation strategies relying on studies based on physical concepts and processes derived from water quantity studies, which are difficult to transfer between catchments. Hence, a more holistic approach incorporating chemical processes compared to the current piecemeal solutions could significantly improve the protection of key environmental values in a region. Furthermore, urban water quantity mitigation measures are generally designed to reduce the impacts of high-flow events. This research suggests that fairly frequent occurring rainfall events, such as 1-year design rainfall events, could carry significant heavy metal and PAH concentrations in both particulate and dissolved fractions. Hence, structural measures, designed to decrease quantity and quality impact on receiving waters during 10 or 20-year Average Recurrence Interval (ARI) events could be inefficient in removing the majority of PAHs and heavy metals being washed off during more frequent events. The understanding of physical and chemical processes in urban stormwater management could potentially lead to significant improvements in pollutant removal techniques which in turn could lead to significant socio-economic advantages. This project can serve as a baseline study for urban water quality investigations in terms of adopting new methodology and data analysis.

Accurate and reliable estimations are the most important factors for the development of efficient stormwater pollutant mitigation strategies. Modelling is the primary tool used for such estimations. The general architecture of typical modelling approaches is to replicate pollutant processes along with hydrologic processes on catchment surfaces. However, due to the lack of understanding of these pollutant processes and the underlying physical parameters, the estimations are subjected to gross errors. Furthermore, the essential requirement of model calibration leads to significant data and resource requirements. This underlines the necessity for simplified and robust stormwater pollutant estimation procedures. The research described in this thesis primarily details the extensive knowledge developed on pollutant build-up and wash-off processes. Knowledge on both build-up and wash-off were generated by in-depth field investigations conducted on residential road and roof surfaces. Additionally, the research describes the use of a rainfall simulator as a tool in urban water quality research. The rainfall simulator was used to collect runoff samples from small-plot surfaces. The use of a rainfall simulator reduced the number of variables which are common to pollutant wash-off. Pollutant build-up on road and roof surfaces was found to be rapid during the initial time period and the rate reduced when the antecedent dry days increase becoming asymptote to a constant value. However, build-up on roofs was gradual when compared to road surfaces where the build-up on the first two days was 66% of the total build-up. Though the variations were different, it was possible to develop a common replication equation in the form of a power function for build-up for the two surface types with a as a multiplication coefficient and b as a power coefficient. However, the values for the two build-up equation coefficients, a, and b were different in each case. It was understood that the power coefficient b varies only with the surface type. The multiplication coefficient varies with a range of parameters including land-use and traffic volume. Additionally, the build-up observed on road surfaces was highly dynamic. It was found that pollutant re-distribution occurs with finer particles being removed from the surface thus allowing coarser particles to build up. This process results in changes to the particle size composition of build-up. However, little evidence was noted of re-distribution of pollutants on roof surfaces. Furthermore, the particulate pollutants in both road and roof surfaces were high in adsorption capacity. More than 50% of the road and more than 60% of the roof surface particulates were finer than 100 μm which increases the capacity to adsorb other pollutants such as heavy metals and hydrocarbons. In addition, the samples contained a significant amount of DOC which would enhance the solubility of other pollutants. The wash-off investigations on road and roof surfaces showed a high concentration of solid pollutants during the initial part of events. This confirmed the occurrence of the 'first flush' phenomenon. The observed wash-off patterns for road and roof surfaces were able to be mathematically replicated using an exponential equation. The exponential equation proposed is a modified version of an equation proposed in past research. The modification was primarily in terms of an additional parameter referred to as the 'capacity factor' (CF). CF defines the rainfall's ability to mobilise solid pollutants from a given surface. It was noted that CF varies with rainfall intensity, particle size distribution and surface characteristics. Additional to the mathematical replication of wash-off, analysis further focused on understanding the physical processes governing wash-off. For this, both particle size distribution and physicochemical parameters of wash-off pollutants were analysed. It was noted that there is little variation in the particle size distribution of particulates in wash-off with rainfall intensity and duration. This suggested that particle size is not an influential parameter in wash-off. It is hypothesised that the particulate density and adhesion to road surfaces are the primary criteria that govern wash-off. Additionally, significantly high pollutant contribution from roof surfaces was noted. This justifies the significance of roof surfaces as an urban pollutant source particularly in the case of first flush. This dissertation further describes a procedure to translate the knowledge created on pollutant build-up and wash-off processes using small-plots to urban catchment scale. This leads to a simple and robust urban water quality estimation tool. Due to its basic architecture, the estimation tool is referred to as a 'translation procedure'. It is designed to operate without a calibration process which would require a large amount of data. This is done by using the pollutant nature of the catchment in terms of buildup and wash-off processes as the basis of measurements. Therefore, the translation procedure is an extension of the current estimation techniques which are typically complex and resource consuming. The use of a translation procedure is simple and based on the graphical estimation of parameters and tabular form of calculations. The translation procedure developed is particularly accurate in estimating water quality in the initial part of runoff events.

Extensive research has been undertaken to improve the robustness of runoff quantity predictions for urban catchments. However, equally robust predictions for runoff quality have yet to be attained. Past studies addressing this issue have typically been confined to the use of simple conceptual or empirical models which forgo the tedious steps of providing a physical representation of the actual system to be modelled. Consequently, even if the modelling results for the test catchments are satisfactory, the reliability and applicability of these models for other catchments remain uncertain. It is deemed that by employing process-based, deterministic models, many of these uncertainties can be eliminated. A lack of understanding of the hydrological processes occurring during storm events and the absence of good calibration data, however, hamper the advancement of such models and limit their use in the field. This research proposes that the development of a hydrologic model based on the kinematic wave equations linked to an advection-dispersion model that simulates pollutant detachment and transport will improve both runoff quantity and quality simulations and enhance the robustness of the predictions. At the very worst, a model of this type could still highlight the underlying issues that inhibit models from reproducing the recorded historical hydrographs and pollutographs. In actual fact, this approach has already been applied by various modellers to simulate the entrainment of pollutants from urban catchments. Also, the paradigm shift to using the Water Sensitive Urban Design (WSUD) approach in designing urban stormwater systems has prompted the need to differentiate the various sources of pollutants in urban catchments such as roads, roofs and other impervious surfaces. The primary objective of the study reported herein is to model runoff quantity and quality from small urban catchments, facilitated by the procurement of the necessary field data to calibrate and validate the model via implementation of a comprehensive field exercise based in Sydney. From a water quality perspective, trace metals were selected as the foci. The study outcomes include the formulation of a linkage of models capable of providing accurate and reliable runoff quantity and quality predictions for the study catchments by taking into consideration: - The different availability of pollutants from urban catchments, i.e. roads vs. roofs; - The build-up characteristics of pollutants on the distinct urban surfaces and their spatial distribution; - The contribution of rainwater to urban runoff pollution; - The partitioning of pollutants according to particulate bound and dissolved phases; - The respective role of rainfall and runoff in the detachment and entrainment of pollutants; - The influence of particle properties such as particle size distribution and density on pollutant transport; and - The relationship associating particulate bound metals to suspended solids. The simulation results obtained using the proposed model were found to be suitable for modelling the detachment and transport of pollutants for small urban catchments. Interpretation of these results reveals several key findings which could help to rectify shortcomings of existing modelling approaches. Even though the robustness of the model presented here may not translate into a significant improvement in the overall robustness of model predictions, the physical basis on which this process-based model was developed nevertheless provides the flexibility necessary for implementation at alternative sites. It is also shown that the availability of reliable runoff data is essential for implementation of the model for other similar urban catchments. In conclusion, the proposed model in this study will serve as a worthy tool in future urban catchment management studies.

Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2015-05-07T14:06:12Z No. of bitstreams: 2 Dissertação - Luciana Inácio Pauletti - 2012.pdf: 2287630 bytes, checksum: 392dd39420f8918a2239eaf29eea5ee0 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2015-05-07T14:08:33Z (GMT) No. of bitstreams: 2 Dissertação - Luciana Inácio Pauletti - 2012.pdf: 2287630 bytes, checksum: 392dd39420f8918a2239eaf29eea5ee0 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2015-05-07T14:08:33Z (GMT). No. of bitstreams: 2 Dissertação - Luciana Inácio Pauletti - 2012.pdf: 2287630 bytes, checksum: 392dd39420f8918a2239eaf29eea5ee0 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2012-09-21 / The stormwater runoff in urban areas is an important source of non-point pollutants. This study aimed to quantify the build-up and wash-off of pollutants, particularly metals, water runoff from a paved surface urban Goiânia. Studies to estimate the processes of build-up and wash-off are still incipient in Brazil. We evaluated twelve plots paved with size of 3m2, located in a public parking lot, where they were analyzed on build-up and wash-off in June and July 2012. To wash-off was used a rainfall simulator in three intensities, 69 mm/h, 109 mm/h and 180 mm/h. Quantitation of accumulation in sampled surfaces determined load per m2 to obtain the coefficient build-up as well as for the analysis of the influence of background dried days before sampling campaigns. The build-up was adjusted at four possible equations for use in models water quality: (1) Linear, (2) Power (3) Exponential, and (4) Michaelis-Menton by obtaining the best fit. The water quality parameters analyzed were used for calculation of Average Concentration Event (CME), building polutogramas, coefficient of wash-off and correlation analyzes. The accumulation rate obtained was, on average, 8.53 g/m2dia, and more days dry, the greater the accumulation of pollutants. Levels of metals were found in all analyzed plots for all simulated events in different periods. There sharp and direct correlation between variables, particularly suspended solids and metals. The intensity of rain on the wash-off was clear, since the simulated rain intensity shifted with greater dirtier. Parameters were obtained for modeling the quality of rainwater. / O presente trabalho teve como objetivo quantificar o acúmulo (build-up) e carreamento (wash-off) de poluentes, principalmente metais, na água do escoamento de uma superfície pavimentada urbana de Goiânia. Os estudos para estimativa dos processos de build-up e wash-off são ainda insipientes no Brasil. Foram avaliadas doze parcelas experimentais asfaltadas, com dimensão de 3m2, situadas em um estacionamento público, onde foram realizadas as determinações de build-up e wash-off nos meses de junho e julho de 2012. Para wash-off foi utilizado um simulador de chuvas em três intensidades, 69 mm/h, 109 mm/h e 180 mm/h. A quantificação do acúmulo nas superfícies amostradas determinou a carga por m2 para obtenção do coeficiente de build-up, bem como para a análise da influência dos dias secos antecedentes antes das campanhas amostrais. O build-up foi ajustado nas quatro equações: (1)Linear, (2)Potencial, (3)Exponencial, e (4)Michaelis-Menton, com a qual se obteve o melhor ajuste. As análises de qualidade de água de escoamento permitiram o cálculo da Concentração Média do Evento (CME), construção de polutogramas, determinação do coeficiente de wash-off e análises de correlação. A taxa de acúmulo obtida foi, em média, de 8,53g/m2dia, sendo que quanto mais dias secos antecedentes à coleta, maior o acúmulo de poluentes. Foram encontrados metais (cromo, cádmio, cobre, chumbo, níquel, zinco, manganês e ferro) em todas as parcelas experimentais para todos os eventos simulados nos diferentes períodos. Verificou-se correlação direta e acentuada entre as variáveis avaliadas, principalmente entre sólidos suspensos e metais. O efeito da intensidade de chuva sobre o wash-off ficou evidente, visto que as chuvas simuladas com maior intensidade deslocaram mais poluentes. Neste estudo foram obtidos parâmetros para a modelagem da qualidade das águas pluviais.

This thesis is organized in three different parts. In the first part Ericsson’s methods fordeveloping and deploying the existing knowledge are analyzed. In the second part we analyzethe competence build-up for consultants within a technical domain that is constantly evolving.The third part is an evaluation, on an overview level, of a new organizational concept thatEricsson launched. The concept is a way to globally manage knowledge and competencewithin different technical domains. The concept is called Global Competence Center.The method applied was interviews, as a first step to learn about the subject and also forourselves to get to know the organization in which we conducted our research. Interviewswere also used in order to answer our research questions. The employees gave their view onwhat makes learning more efficient. Examples are hands-on, reality based and problemoriented tasks. This was combined with studies of literature and our own experiences oflearning.Our study shows that a combination of different methods for developing and deployingknowledge and building competence seems to be most suitable. This is based on theinterviewees’ experiences and the principles of a theory about adult learning called andragogy.From the interviews, we also received suggestions about work improvements for theconsultants’ work roles. A competence program was developed for the building ofcompetence amongst consultants. The program uses case studies and mentorship as two of themethods, which both apply to the theory of andragogy. / Den här rapporten är uppdelad i tre olika delar. I den första delen analyseras Ericssonsmetoder för att utveckla och sprida existerande kunskap. I den andra delen analyserar vikompetensuppbyggnaden för konsulter inom en teknisk domän som ständigt förändras. Dentredje delen är en utvärdering, på en översiktlig nivå, av ett nytt organisatoriskt koncept somEricsson har startat. Konceptet är ett sätt att hantera kunskap och kompetens inom olikatekniska domäner. Konceptet kallas för Global Competence Center.Metoden vi använde var intervjuer, som ett första steg för att lära oss ämnet men också för attlära oss organisationen som vi utförde vår studie i. Intervjuer användes också för att kunnabesvara våra frågeställningar. De anställda gav sin syn på vad som gör lärande mer effektivt.Exempel är hands-on, verklighetsbaserade och problembaserade uppgifter. Arbetetkombinerades med litteraturstudier och våra egna erfarenheter av lärande.Vår studie visar att en kombination av olika metoder, för att utveckla och sprida kunskap ochbygga kompetens, verkar vara mest lämplig. Detta är baserat på de intervjuades erfarenheteroch principerna av en teori om vuxnas lärande, kallad andragogik. Från intervjuerna fick viockså förslag på förbättringar för konsulternas arbetsroller. Ett kompetensprogramutvecklades för att bygga kompetens bland konsulter. Programmet använder case-studier ochmentorskap som två av metoderna, vilka båda drar nytta av hur teorierna om andragogiktillämpas.

Den här rapporten är uppdelad i tre olika delar. I den första delen analyseras Ericssonsmetoder för att utveckla och sprida existerande kunskap. I den andra delen analyserar vikompetensuppbyggnaden för konsulter inom en teknisk domän som ständigt förändras. Dentredje delen är en utvärdering, på en översiktlig nivå, av ett nytt organisatoriskt koncept somEricsson har startat. Konceptet är ett sätt att hantera kunskap och kompetens inom olikatekniska domäner. Konceptet kallas för Global Competence Center.Metoden vi använde var intervjuer, som ett första steg för att lära oss ämnet men också för attlära oss organisationen som vi utförde vår studie i. Intervjuer användes också för att kunnabesvara våra frågeställningar. De anställda gav sin syn på vad som gör lärande mer effektivt.Exempel är hands-on, verklighetsbaserade och problembaserade uppgifter. Arbetetkombinerades med litteraturstudier och våra egna erfarenheter av lärande.Vår studie visar att en kombination av olika metoder, för att utveckla och sprida kunskap ochbygga kompetens, verkar vara mest lämplig. Detta är baserat på de intervjuades erfarenheteroch principerna av en teori om vuxnas lärande, kallad andragogik. Från intervjuerna fick viockså förslag på förbättringar för konsulternas arbetsroller. Ett kompetensprogramutvecklades för att bygga kompetens bland konsulter. Programmet använder case-studier ochmentorskap som två av metoderna, vilka båda drar nytta av hur teorierna om andragogiktillämpas. / This thesis is organized in three different parts. In the first part Ericsson’s methods fordeveloping and deploying the existing knowledge are analyzed. In the second part we analyzethe competence build-up for consultants within a technical domain that is constantly evolving.The third part is an evaluation, on an overview level, of a new organizational concept thatEricsson launched. The concept is a way to globally manage knowledge and competencewithin different technical domains. The concept is called Global Competence Center.The method applied was interviews, as a first step to learn about the subject and also forourselves to get to know the organization in which we conducted our research. Interviewswere also used in order to answer our research questions. The employees gave their view onwhat makes learning more efficient. Examples are hands-on, reality based and problemoriented tasks. This was combined with studies of literature and our own experiences oflearning.Our study shows that a combination of different methods for developing and deployingknowledge and building competence seems to be most suitable. This is based on theinterviewees’ experiences and the principles of a theory about adult learning called andragogy.From the interviews, we also received suggestions about work improvements for theconsultants’ work roles. A competence program was developed for the building ofcompetence amongst consultants. The program uses case studies and mentorship as two of themethods, which both apply to the theory of andragogy.

Trend towards downsizing the product size and at the same time to bring more functionality in electronic products, demands electrically interconnecting several miniaturized electronic components with high counts of I\Os (Input/Out put) on smaller and smaller size printed wiring boards [PWB]. These miniature components occupy lower foot print area but require higher routing interconnection densities. However, the conventional multilayer board technologies exhibit limitations when there is need to connect very high I\O components such as ball grid arrays, which require blind and buried interconnections within the multilayer mono-block. This limitation has given raise to newer methods of multi layer construction. Build–up multilayer PWB is now the technology of choice for enhanced routing capability including blind and buried interlayer connections. Build up methods are based on making very small vias within dielectric layers followed by metalisation. Typically blind and buried vias are very small, and hence called “micro vias” connecting the layers selectively within the multilayer mono-block. Buried vias make the interconnection between the consecutive layers, and blind vias connect the surface layers to any one of the interior layers in the build up multilayer board. If the blind vias are filled with a dielectric, the entire top and bottom surface area becomes available for high -density component mounting. The crux in build up board technologies is the method of creating micro-holes; a micro hole is a hole, which is less than 150 micro meter in diameter. Efforts are made to replace existing metalising techniques with “paste filling” methodologies, which would result in “SOLID CONDUCTING VIAS” CALLED AS “MICRO -INTERCONNECTS” The work reported in this thesis aims at demonstrating one such innovative ‘solid conducting via’ formation without using any of the known micro-hole formation techniques. Based on the results obtained some useful conclusions have been drawn which will perhaps go a long way in the name of “PRINTED PILLAR TECHNOLOGY” a novel methodology for building multilayer suitable for very high I\O components such as “ball grid arrays.”