M.Tech. (Department of Chemical Engineering, Faculty of Engineering and Technology), Vaal University of Technology / Corrosion responses of some carbon steels, stainless steel and copper alloys in the presence of a culture of bacteria (referred to as SRB-Sulphate-reducing bacteria) found in industrial heat exchangers, was studied to recommend best alloys under this service condition, with techno-economic consideration. Water from cooling towers in three plants in a petrochemical processing complex were analysed for SRB presence. Two of the water samples showed positive indication of SRB presence. The mixed cultures obtained from plant one were grown in prepared media and incubated at 35 °C for 18 days. Potentiodynamic polarisation studies in anaerobic conditions were done on the selected alloys in aqueous media with and without the grown SRB. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) were then used to study the corrosion morphology and corrosion products formation. The voltamograms show higher icorr for alloys under the SRB compared to the control media, indicating the SRB indeed increased the corrosion rates. The surface analysis showed pitting on steel alloy ASTM A106-B. Localised attack to the grain boundaries on a selective area, was seen on ASTM A516-70 dislodging the grains, and intergranular corrosion was seen throughout the exposed area of ASTM A179. Copper alloys showed pitting on ASTM B111 grade C71500 (70-30), and denickelification on ASTM B111 grade C70600 (90-10), and is a good alternative material for use apart from carbon steel alloys, recording a low corrosion rate of 0.05 mm/year. The EDS analysis supported the findings showing higher weight percent of iron and sulphur on surface of the alloys after exposure to the SRB media. This implies that the presence of the sulphur ion indeed increased the corrosion rate. ASTM A516-70 carbon steel was chosen as a suitable alternative material to the stainless steel in this environment. The Tafel plot recorded a corrosion rate of 1.08 mm/year for ASTM A516-70 when exposed to SRB media.

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Caching is a fundamental technique widely used in the field of computing to reduce network traffic, server load, and latency. Storing frequently accessed data in a high-speed cache layer can make future requests process faster by involving fewer system components when generating and serving the response. Kalix is a software product that demands a caching solution since it faces latency and is frequently processing partially repeated queries. However, a cache does not guarantee improved performance, which is why the main problems of caching are: determining what content to cache, when to insert or remove cache content, implementing the caching logic, and deciding where to store the cache efficiently. Therefore, this paper theoretically investigates where a cache solution should be implemented within the Kalix system architecture to decrease latency and server load, and evaluates the subsequent cache implementation experimentally. As a result, a client-side cache is implemented which decreases the latency of Kalix by up to 74%, while reducing the I/O load and memory utilization on the server by 98%. The reason for the decrease is that the cache in the client can directly serve the majority of the content, allowing the servers of Kalix to do substantially fewer computations. The evaluation acts as a recommendation for the company behindKalix, Polystar, as to if a cache is beneficial and where the cache can efficiently be deployed, and this paper gives valuable insights into the decision-making of cache placement. Concludingly, implementing the cache positively impacts the Kalix user experience.

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Master of Science / Department of Civil Engineering / Natalie Mladenov / The detrimental health effects of arsenic (As) contamination have motivated the study of As mobility around the globe. The variability in naturally occurring As concentration is due to variation in geology and climate. In arid environments with high evaporation, ecohydrology and As desorption under alkaline pH are thought to be responsible for high As concentrations. In reducing groundwater, on the other hand, microbial iron (Fe) reductive dissolution is known to release As into solution. In such environments, As-sulfide minerals precipitation and vegetation uptake could contribute to re-distribution of As. The Okavango Delta is an arid-zone wetland punctuated by ten of thousands of islands, and the reducing groundwater beneath these islands have dissolved As as high as 3000 µg•L[superscript]-1. Ecohydrologic controls are thought to contribute to the elevated As level; however dissolution of Fe-containing sediments has been proposed as the initial step in releasing As from sediment to the groundwater. To test the consistency of the hypothesized mechanisms, four islands were sampled in January 2013. The goal of this thesis is to: 1) provide more evidence on the zones of elevated As in groundwater of four islands, 2) gain understanding on the influence ecohydrology (i.e., evapotranspiration) on high As in groundwater, 3) evaluate the sediment of microbial community composition, and 4) gain new insights into the behavior of DOM along the groundwater flow path. The findings show zones of elevated As in all four islands. The ecohydrologic controls provide information on the location of high As and solute accumulation. Microbial analyses suggest DNA sequences collected were grouped within lineages that contain organisms capable of dissimilatory Fe reduction and sulfate reduction. This supports evidence from previous study that sulfide produced by microbial sulfate reduction is available for As-sulfide mineral formation. The variation of DOM characteristics could influence As solubility and reactivity. In addition, carbonate alkalinity and increase pH may contribute to As mobility further along the flow path. In this arid and reducing groundwater, we find that ecohydrologic and biogeochemical processes have a fundamental role in As mobility.

Indigenous Peoples and REDD+: A Critical Perspective / Indigenous Peoples' Biocultural Climate Change Assessment Initiative (IPCCA) / November 2014 / Public Political Ecology Lab / Executive Summary: REDD+ stands for Reducing Emissions from Deforestation and forest Degradation in developing countries (REDD) and includes conservation, sustainable forest management and the enhancement of carbon stocks (the +). An international initiative negotiated under the United Nations Framework Convention on Climate Change (UNFCCC), REDD+ has been proposed as a central strategy for mitigating climate change in forests. While advocates highlight the cost effectiveness and social and ecological co-benefits that can be generated through REDD+, many indigenous and forest dependent groups have expressed concerns about the potential effects of projects on their access to land and resources. This report identifies key issues facing indigenous and forest-dependent communities with respect to REDD, and is based on existing academic literature and more current reports by NGOs and indigenous organizations. We first lay out a brief history of REDD+, interrogate its key assumptions, and discuss major issues of concern. We then discuss REDD+ as it relates to indigenous peoples and forest-dependent communities. This is followed by a series of case studies of developing countries participating in REDD+. We conclude with a discussion of the principal elements for an alternative vision for REDD+ that takes seriously the rights of indigenous peoples. / / Resumen Ejecutivo REDD+ es acrónimo para Reducing Emissions from Deforestation and forest Degradation (Reducir las Emisiones por Deforestación y Degradación de bosques) (en países en desarrollo). Incluye acciones para la conservación, el manejo sustentable de bosques y el aumento en los suministros de carbono (el +). Como una iniciativa internacional negociada bajo el United Nations Framework Convention on Climate Change (UNFCCC) (Convención Marco de Naciones Unidas sobre el Cambio Climático), REDD+ ha sido propuesto como una estrategia principal para mitigar el cambio climático en bosques. Aunque sus defensores enfatizan la eficacia financiera y los co-beneficios sociales y ecológicos que se pueden generar a través del REDD+, muchos grupos indígenas y de gente quien depende de bosques para su sustento tienen preocupaciones acerca de los posibles efectos de los proyectos sobre el acceso a la tierra y los recursos forestales. Este informe identifica los problemas principales que enfrentan las comunidades indígenas y gente dependiente de bosques con REDD. Está basado en la literatura académica existente y otros reportes actuales escritos por organizaciones no gubernamentales (ONGs) y organizaciones indígenas. Primero proveeremos una historia breve de REDD+, evaluaremos las suposiciones principales y discutiremos los problemas de mayor preocupación. Luego describiremos la relación entre REDD+ y los pueblos indígenas y comunidades dependientes de bosques. Esto será seguido por una colección de casos de estudio en los países en desarrollo que participan en REDD+. Concluiremos con una discusión de los elementos principales para una visión alternativa de REDD+ que toma en cuenta los derechos de los pueblos indígenas.

Title: Reducing Supplier Lead time – a case study on Supplier Lead Time at purchasing companies Authors: Johanna Jönsson and Melinda Luong Tutor: Dr. Åsa Gustavsson Examiner: Dr. Lars-Olof Rask Course code: 4FE06E - Master Thesis _________________________________________________________________________ Research questions: ●  How are companies working with and defining Supplier Lead Time? ●  What activities are included to reduce Supplier Lead Time? ●  How can companies further develop their work to reduce Supplier Lead Time? Purpose: The purpose of this Master Thesis is to describe and explain how purchasing companies are working to reduce Supplier Lead Time, in order to maintain or achieve an efficient and flexible supply chain. Moreover the study aims to recommend what approaches companies could further use to reduce Supplier Lead time. Method: To answer these research questions the authors have done two case studies. The theoretical material has been collected and processed, which has formed the basis for the semi-structured interview guide that was answered by the interviewees. The authors also attended meetings to get other inputs about the subject. Conclusion: IKEA Components are today taking different actions to improve the SLT but can improve their volume agreements (AGV) by aligning all involved parts and have a functional leader that makes sure that they follow it up. At IKEA IMS the authors recommend them to work with volume commitments with suppliers and develop a clearer structure for who is responsible for improving the SLT and evaluating it. Keywords Supply chain management, Supplier Lead Time, Reducing Supplier Lead Time, Organization management, Performance evaluation

The composition of the diet has been recently researched as an important factor in controlling excess body fat, and thus obesity. Along with dietary modifications, it has been stressed to incorporate behavior modification and daily physical activity to promote weight loss. A comprehensive program incorporating all three components is the suggested treatment for long term weight maintenance. This study investigated a 12 week low dietary fat education program including behavior modification and physical activity to promote weight loss in the abdominally obese. There were eight experimental subjects and four controls. Measurements assessed were height, weight, percent body fat, body mass index, waist/hip ratio, ideal body weight, daily caloric intake, percent dietary fat intake, percent saturated fat intake, saturated fat gram intake, physical activity assessments and resting metabolic rate. Results showed significant differences between the experimental and control groups for calorie intake, body weight, ideal body weight and saturated fat gram intake at post-intervention. Percent of dietary fat intake decreased from baseline to follow-up in the experimental group, but did not reach significance. There was a 33% decrease in saturated fat gram intake from baseline to follow-up in the experimental group. A significant decrease in daily caloric intake occurred in the experimental group from baseline to post-intervention. The decrease in body weight could not be directly correlated to dietary fat intake, although they did have a tendency to move in the same direction. These data suggest the weight management program in this study was successful at decreasing body weight, daily caloric intake, dietary fat intake and saturated fat intake.The qualitative interview revealed obstacles faced by the subjects. The most common difficulties in adhering to the program included time constraints, travel, lack of a structured physical activity component, social pressures triggering eating behavior, feeling of guilt when prioritizing time for oneself and lack of continued support and education through class sessions. Individual motivational factors existed. Therefore, personalized attention and a continued support system would be beneficial as part of the treatment program for success in changing lifestyle behaviors.In conclusion, this data suggest an educational program encouraging decreased dietary fat intake, behavior modification and increased daily physical activity without a calorie controlled plan can promote weight management in the abdominally obese. / Institute for Wellness

The goal of quantifying the woody cover and biomass of tropical savannas, woodlands and forests using satellite data is becoming increasingly important, but limitations in current scientific understanding reduce the utility of the considerable quantity of satellite data currently being collected. The work contained in this thesis reduces this knowledgegap, using new field data and analysis methods to quantify changes using optical, radar and LiDAR data. The first paper shows that high-resolution optical data (Landsat & ASTER) can be used to track changes in woody vegetation in the Mbam Djerem National Park in Cameroon. The method correlates a satellite-derived vegetation index with field-measured canopy cover, and the paper concludes that forest encroached rapidly into savanna in the region from 1986-2006. Using the same study area, but with radar remote sensing data from 1996 and 2007 (ALOS PALSAR & JERS-1), the second paper shows that radar backscatter correlates well with field-measured aboveground biomass (AGB). This dataset confirms the woody encroachment within the park; however, in a larger area around the park, deforestation dominates. The AGB-radar relationships described above are expanded in the next paper to include field plots from Budongo Forest (Uganda), the Niassa Reserve (north Mozambique), and the Nhambita Community Project (central Mozambique). A consistent AGB-radar relationship is found in the combined dataset, with the RMSE for predicted AGB values for a site increasing by <30 %, compared with a site-specific equation, when using an AGB-radar equation derived from the three other sites. The study of the Nhambita site is extended in the following paper to assess the ability of radar to detect change over short time periods in this environment, as will be needed for REDD (Reducing Emissions from Deforestation and Degradation). Using radar mosaics from 2007 and 2009, areas known (from detailed ground data) to have been degraded decreased in AGB in the radar change detection, whereas areas of agroforestry and forest protection showed small increases.

In remote areas without conventional cellular service, satellite communication is often the only viable option. Handheld devices for use with satellite communication networks require a high transmit power to obtain a reliable signal. The need for a high transmit power makes it difficult for the device to meet specific absorption rate (SAR) restrictions. An adaptive beam forming technique for shaping radiation away from the user’s head is proposed. This technique uses a back-to-back patch antenna design with an impedance monitoring based system capable of adaptively controlling the pattern of the antenna. The adaptive antenna system was designed, simulated, fabricated, and measured. The system could detect a head phantom within 3 cm of the antenna. SAR levels were verified to be within safety restrictions at 3 cm through simulation. By turning off the patch facing the user’s head when the phone is transmitting, and the user’s head is within 3 cm, it was shown that SAR levels could be reduced to safe levels. / February 2017