Chromium is used in many processing applications, which has led to the formation of chromium(VI) waste. Cr(VI) is an unstable, mobile carcinogen, which is interchangeable with Cr(III) under certain environmental conditions. Management of this waste, however, is often not considered. Mine under investigation is an example of such historic mismanagement. During the second World War, Cr(VI) waste was transferred to the study site from areas where leather products were made for the war effort. This waste was not managed appropriately in the past and with time Cr(VI) leached into the groundwater and possibly surface water resources. As these water resources are used for domestic and agricultural water supply, this may have serious effects on the human and environmental health in the area. Some of the major Cr(VI) effects on human and animal health include malignant tumours, skin irritation, respiratory and reproductive system damage. Lung cancer is of concern when Cr(VI) is inhaled and stomach tumours occur when this chemical pollutant is ingested. The effects of Cr(VI) on plants include the disruption of shoot and root elongation, and if it accumulates enough within the plant can cause ingested health problems for humans and animals. Water quality guidelines state that the Target Water Quality Range for Cr(VI) in drinking water should not exceed 0.05 mg/L. Prolonged exposure of values higher than this target value has adverse health effects and may result in cancer. The study site has a scarcity in water sources and therefore requires good quality water resources. This study aims to identify and use biomarkers to assist in the hydrological characterization of the mine. Available mitigation options can be implemented once it is known how the water in the area moves and distributes Cr(VI) pollution. A biomarker is an indicator of a biological state, which in turn can be used to assist in characterizing the chemical conditions of the sub-surface. Bacteria can aid as environmental biomarkers as they are sensitive and specific to the environmental conditions in which they flourish. In this way they give a good indication of the environmental condition and any possible pollution. Due to the fact that ground- and surface water are integrated resources, it is likely that if one is impacted by pollution, it will indirectly impact the other one. Therefore, the biomarkers identified can be used to characterize water pollutants that are present in ground- and some surface water resources. A description of the study site is provided, wherein the climate, elevation, geology, land use, geohydrology, hydrochemistry and surface water are documented. These factors help to identify and clarify the sources and pathways that water and the pollution would follow. Ten water samples, from surface and groundwater, were obtained in two separate sampling opportunities. The first analysis of the water samples included the determination of the chemical constituents. Two of these constituents analyzed were the total Cr and individual Cr(VI) levels. Six water samples had excessively high Cr values (exceeding the Water Quality Target Range of drinking water and water agricultural use). These values ranged from 0.1 – 3.9 mg/L. The 6 samples with excessive Cr(VI) values were used for the microbial analyses. The microbial analyses consisted of DAPI (4’,6-diamidino-2-phenylindole ) staining, for cell enumeration, and molecular analyses. The molecular analyses included polymerase chain reaction (PCR), denaturing gradient gel electrophoresis (DGGE) and sequencing applications concluded in the laboratory. Fifteen bands, representing different organisms, were removed from the DGGE polyacrylamide gel and processed for sequencing. The organisms that were present in the sample were uncultured Cyanobacterium, Sediminibacterium salmoneum, uncultured Bacteroidetes bacterium, uncultured betaproteobacterium, uncultured actinobacterium, uncultured Rhodocyclaceae, uncultured Chloroflexi bacterium and uncultured delta-proteobacterium. According to literature most of these organisms may adapt the ability to either reduce Cr(VI) or resist any effect of Cr(VI) in the environment. Two of the bands were highly unidentified organisms, which means that these organisms have not yet been cultured or identified in any sense. The reason for this is that most microorganisms have not yet been documented. This also makes it difficult to identify the exact bacterial strain present within the samples. The deoxyribonucleic acid (DNA) sequences of the different organisms were very different from each other, when compared by a dendrogram. This means that there was a diverse community present within the samples. Electrical conductivity profiles were conducted in the monitoring boreholes to identify possible fracture positions. The total chromium and chromium(VI) levels were documented and compared. Other chemical factors were analysed and those of high value, such as chloride, nitrate and chromium measurements, were used for statistical analyses and comparison with the biomarkers present in the sample. A positive correlation was found between the sample sites and the organisms present within each. It was noted that different communities have different metabolic activities related to susceptibility and will therefore differ under specific environmental conditions. The microorganisms that were present in the 6 water samples all have the ability to either resist or reduce Cr(VI). This means that in Cr(VI) polluted areas they are more likely to flourish than organisms that do not possess this ability. Such susceptible, non-resistant organisms would otherwise occur naturally in a non-polluted environment. From the obtained results it was noted that microorganisms could aid as biomarkers when determining the environmental condition (with respect to Cr(VI) pollution). The bacteria analysed in the samples all indicate a level of chromium pollution, and aided in the determination of pollution sources. These biomarkers can therefore be used to determine the location of other chromium deposits not yet located. / MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2013

No description available.

An experiment was conducted to determine the effects of subjective culture on the usability of computerized systems. The results of the experiment did not provide sufficient evidence to conclude that any of the tested cultural dimensions affected the usability of the product. Analysis of the results indicated that the differences in scores could have been attributable to variables other than those tested and controlled for. This indicated a need to build a more detailed conceptual model of usability before empirical research of this nature can be effectively conducted. Consequently, further work needed to be done to identify the variables that influence usability, and the strategies for controlling for these variables under experimental conditions. Through a literature investigation, the validity of some of the proposed variables was established, and some additional variables were identified. The valid variables were then incorporated into a conceptual model of usability for use in future research endeavors. / Information systems / M. Sc.

L’ingénierie tissulaire est une stratégie médicale qui repose sur la régénération de tissu par les cellules avec ou sans matériaux. Pour maîtriser cette synthèse, il faut comprendre la cellule comme une part intégrante du tissu. Hormis ses interactions biochimiques avec son support, la cellule interagit également mécaniquement avec son environnement. Elle s’accroche à ce dernier et évalue sa dureté pour adapter sa réponse biologique. Dans cette étude, j’ai développé des modèles numériques pour analyser l’influence de la rigidité du substrat sur le comportement mécanique de la cellule, sur sa structure contractile interne et les efforts qu’elle génère. En d’autres termes, j’ai essayé de comprendre comment la cellule ressent la rigidité de son environnement. De plus, au lieu de me focaliser sur les propriétés mécaniques quantitatives, j’ai cherché à développer un modèle conceptuel simplifié plus proche de la structure cellulaire. / Tissue engineering is a medical strategy based on utilizing cells and materials to regenerate a new tissue. Yet, it involves intertwined interactions that allow cells to act as integrated parts of an organ. In addition to chemical reactions, the cell interacts mechanically with its environment by sensing its rigidity. Here, we used several computational models to understand how substrate rigidity affects a cell’s structure as it adheres and spreads on it. In other words we tried to understand the way a cell feels how soft or hard it surrounding is, how it affects its internal structure and the forces that transit within it. In addition, instead of focusing on mechanical properties, we developed a simplified, yet coherent conceptual understanding of the cellular structure.

[pt] Esta tese apresenta uma proposta de modelo conceitual para a produção do açaí (Euterpe precatoria) no Estado do Amazonas, a partir de uma reflexão sobre metodologias emergentes de design sustentável. Tais metodologias buscam integrar as dimensões ambiental, econômica e social aos processos de desenvolvimento de produtos. Na pesquisa, conceitos de ecodesign, design social, design participativo, design sustentável e tecnologia apropriada são abordados. Foi realizado um levantamento dos impactos ambientais e sociais observados no modelo produtivo do açaí (Euterpe precatoria) do Amazonas, tendo como objeto de estudo a Cooperativa de Açaí de Codajás, e em seguida foi elaborada uma proposta de modelo conceitual para a produção do açaí na região, buscando responder aos princípios ambientais e priorizar a responsabilidade socioeconômica, visando ao desenvolvimento da região e à melhoria da qualidade de vida dos agricultores envolvidos no processo. / [en] This thesis presents a proposal of a conceptual model for the production of açaí (Euterpe precatoria) in the State of Amazonas, based on a reflection on emerging sustainable design methodologies. These methodologies seek to integrate the environmental, economic and social dimensions into the product development processes. In the research, concepts of ecodesign, social design, participatory design, sustainable design and appropriate technology are addressed. A survey of the environmental and social impacts observed in the açaí (euterpe precatoria) production model of Amazonas was carried out, having the Cooperativa de Acaí de Codajás as the object of study. In the sequence, a conceptual model was proposed for the production of the açaí in the region, seeking to respond to environmental principles and to prioritize socio-economic responsibility, aiming at the development of the region and the improvement of the quality of life of farmers involved in the process.

Made available in DSpace on 2016-12-23T14:33:47Z (GMT). No. of bitstreams: 1 Alex Pinheiro das Gracas.pdf: 2761846 bytes, checksum: a904945394b1c705b72df3268f5bdab8 (MD5) Previous issue date: 2010-08-27 / The adoption of ontologically well founded languages for building ontologies has acquiring more adopters, however its widespread use stumble on using difficulties by inexperienced modelers. This dissertation proposes a methodological guide to support the building of domain ontologies using the ontologically well founded language OntoUML. This guide through the analysis of language structure, restrictions and design patterns helps the designer on the modeling process. Beyond, the building support interactions are used to generate a design rationale. At last, it is presented a Web application implementing the ideas proposed in this work / A adoção de linguagens ontologicamente bem fundamentadas para construção de ontologias, apesar de vir ganhando mais adeptos, esbarra nas dificuldades da utilização desta linguagem por modeladores inexperientes. Este trabalho propõe um guia metodológico para apoiar as construções de ontologias utilizando a linguagem OntoUML Este guia auxilia o projetista no processo de modelagem através do estudo da estrutura da linguagem, suas restrições sintáticas e padrões de projetos. Além disso, as interações com o modelador na utilização deste guia são utilizadas para gerar um design rationale do processo de modelagem. Por final é apresentada uma implementação Web de uma ferramenta que demonstra as propostas apresentadas neste trabalho

Crude oil prices impact the world economy and are thus of interest to economic experts and politicians. Oil price’s volatile behaviour, which has moulded today’s world economy, society and politics, has motivated and continues to excite researchers for further study. This volatile behaviour is predicted to prompt more new and interesting research challenges. In the present research, machine learning and computational intelligence utilising historical quantitative data, with the linguistic element of online news services, are used to predict crude oil prices via five different models: (1) the Hierarchical Conceptual (HC) model; (2) the Artificial Neural Network-Quantitative (ANN-Q) model; (3) the Linguistic model; (4) the Rule-based Expert model; and, finally, (5) the Hybridisation of Linguistic and Quantitative (LQ) model. First, to understand the behaviour of the crude oil price market, the HC model functions as a platform to retrieve information that explains the behaviour of the market. This is retrieved from Google News articles using the keyword “Crude oil price”. Through a systematic approach, price data are classified into categories that explain the crude oil price’s level of impact on the market. The price data classification distinguishes crucial behaviour information contained in the articles. These distinguished data features ranked hierarchically according to the level of impact and used as reference to discover the numeric data implemented in model (2). Model (2) is developed to validate the features retrieved in model (1). It introduces the Back Propagation Neural Network (BPNN) technique as an alternative to conventional techniques used for forecasting the crude oil market. The BPNN technique is proven in model (2) to have produced more accurate and competitive results. Likewise, the features retrieved from model (1) are also validated and proven to cause market volatility. In model (3), a more systematic approach is introduced to extract the features from the news corpus. This approach applies a content utilisation technique to news articles and mines news sentiments by applying a fuzzy grammar fragment extraction. To extract the features from the news articles systematically, a domain-customised ‘dictionary’ containing grammar definitions is built beforehand. These retrieved features are used as the linguistic data to predict the market’s behaviour with crude oil price. A decision tree is also produced from this model which hierarchically delineates the events (i.e., the market’s rules) that made the market volatile, and later resulted in the production of model (4). Then, model (5) is built to complement the linguistic character performed in model (3) from the numeric prediction model made in model (2). To conclude, the hybridisation of these two models and the integration of models (1) to (5) in this research imitates the execution of crude oil market’s regulators in calculating their risk of actions before executing a price hedge in the market, wherein risk calculation is based on the ‘facts’ (quantitative data) and ‘rumours’ (linguistic data) collected. The hybridisation of quantitative and linguistic data in this study has shown promising accuracy outcomes, evidenced by the optimum value of directional accuracy and the minimum value of errors obtained.

The concept of health-related quality of life (HRQoL) had been used as a patient reported outcome measure in healthcare settings. It has been conceptualised and measured using validated instruments in the Western scientific community. However, in the Saudi literature, the true meaning of this concept is still lacking. The aim of this study is to explore the gap in literature and define the concept of HRQoL, identify its key domains and conceptualise it as perceived specifically by patients with renal failure and undergoing haemodialysis in Saudi Arabia. This PhD included two strands, an empirical qualitative study and a critical analysis of the HRQoL concept and its measurement in the Western as well as the Saudi literature. Using qualitative research methods, the empirical study was conducted in one centre in the Eastern Region of Saudi Arabia. Twenty two In-depth qualitative interviews were conducted in the Arabic language, recorded, transcribed and translated into English. Thematic analysis was performed to analyse the data as the transcripts were coded, the categories identified and the themes generated. The conceptual analysis of HRQoL was carried out after the review of the Western literature on the quality of life (QoL) conceptual models and the measuring instruments used in renal literature. Systematic review of the Saudi HRQoL literature was performed as well to understand the meaning and methods of measurement of the concept of HRQoL. The conceptual analysis of HRQoL revealed that the concept is poorly defined in the Saudi literature; its measurement was based on instruments that are not culturally-adapted. Hence the findings are subjected to questions of validity and reliability. The QoL conceptual models have been developing in the Western literature as well as measuring instruments for patients with renal failure. However, the adoption of these models or instruments is critical due to social, cultural and religious variations between Saudi Arabia and the Western societies. Seven themes defining HRQoL emerged from the qualitative data; these reflected the subjectivity of the concept. The domains of HRQoL were the physiological, social, psychological, religious and vocational domains. Each of those domains was defined by determinants that affect other domains and the overall HRQoL. These were synthesised into a single definition, which incorporated all five domains. A model of HRQoL of patients undergoing haemodialysis in Saudi Arabia was developed explaining the relationship between the key domains and HRQoL. Healthcare services were discussed as a factor that affects the health status of patients and plays an indirect role in the life quality of this patient group. Hence it was considered as a factor rather than a domain. This study, including the conceptual analysis and the empirical study, illustrates that the concept of HRQoL is highly individual and is affected by the views of individuals living in a specific culture. Additionally, it is affected by the social, cultural and religious backgrounds of those individuals. The conceptualisation of HRQoL in this study was almost similar to the Western conceptualisation, however, the relationships between the key domains of HRQoL and their determinants differed. The social and religious domains were highly influenced by the Arabic culture and the Islamic religion. HRQoL in patients with ESRD in the Eastern Region of Saudi Arabia has a different meaning and conceptualisation from that seen in comparable Western literature. The assessment of HRQoL of patients with renal failure and on haemodialysis in Saudi Arabia requires a culturally-adapted instrument. This would ensure valid and reliable results that could be used in decision-making and the planning of care.

Aunque la publicación de artículos sobre la adaptabilidad y aplicación de las herramientas lean, en el sector agrícola, en las diferentes plataformas de investigación es poco explorado, en especial si se enfoca en el Perú, algunos autores y profesionales han enfatizado su adaptabilidad a este sector. En ese sentido, este artículo propone un marco para la implementación eficiente de las herramientas lean en el sector agrícola de Perú, abordando los desafíos desde una perspectiva operativa y estratégica. Para ello, el artículo se basa en investigaciones científicos publicadas por algunos expertos en la materia de la filosofía lean, estas investigaciones incluyen revisiones de literatura, modelado y casos de éxito. / Although the publication of articles on the adaptability and application of lean tools, in the agricultural sector, in the different research platforms is little explored, especially if it focuses on Peru, some authors and professionals have emphasized its adaptability to this sector . In that sense, this article proposes a framework for the efficient implementation of lean tools in the agricultural sector of Peru, addressing the challenges from an operational and strategic perspective. For this, the article is based on scientific research published by some experts in the field of lean philosophy, this research includes literature reviews, modeling and success stories. / Trabajo de investigación

The work sets out requirements for the implementation of information systems generator. It deals with finding common elements of information systems. Further it specifies requirements for registration of a conceptual model. Then it goes on to describe user's general point of view of systems. Implementation technologies are chosen and architecture of generated systems is designed based on mentioned analysis. Generated systems are designed to provide basic operations for working with items of the system. Moreover, different ways of generating code are discussed. Metamodel of conceptual model is designed and its possible types of representation are discussed. At the end problems which generator deals with are described.