Lake Malawi is a great lake not only because of its size (30,800 km2) but also because of its unique fish diversity. The lake contains the highest number of freshwater fish species in the world. The fish species are hypothesized to have radiated within the lake, which is 1-2 million years old. The collapse of the capture fishery in Lake Malawi between the 1970s and 1990s led to the launch of cage culture of indigenous fish species in 2004 in the south east arm of the lake. While cage culture has been practiced for many years in temperate lakes and seas, the fish farm in Lake Malawi is the first in the African Great Lakes and, therefore, not much information currently exists that is relevant to the impact of cage culture on such a large, species-rich tropical lake. Consequently, a study was done between January and December, 2007, at the fish farm in Lake Malawi to determine potential impacts of cage wastes on the environment. The study found that, just like in temperate systems where 70-87% of C, N and P added through feed get dispersed into the environment, discharges from fish cages in Lake Malawi were between 71-88% of the nutrients added through feed. The discharges were proportional to the amount of feed added so that as production and feed supply increase over time, more cage wastes would be generated and released into the environment. The discharges were exacerbated by poor stocking and feeding regimes. Production periods were longer (mean of 376±42 days) than if recommended stocking and feeding rates were followed. Feed quality may also have affected production performance and waste generation in the cages, but was not studied. The cage wastes were incorporated into the food web and support the wild fishes in the vicinity of the fish farm. Impacts of the cage wastes on the water column and sediments in the vicinity of the cages were minimal during the study period, probably because of rapid and efficient dispersion of the wastes by strong water currents, that averaged 9.3 cm s-1, through the cages and high consumption of the cage wastes by large numbers of wild fishes which aggregated around the cages. The wild fishes also helped to disperse the cage wastes over a larger area through consumption, translocation and defecation. However, as production increases, the amount of cage wastes generated may overwhelm mitigation by dispersion by water currents and consumption by wild fishes, particularly if many cages are deployed close together and interfere with current flows. Based on my observations, a fish farm that produces 15,000 tonnes fish/yr in Lake Malawi would generate 1249, 113 and 21 megamoles/yr of C, N and P, respectively, that are comparable or higher than DOC, TDN and TDP loadings observed in the most disturbed large river systems draining into Lake Malawi. The impacts of these river systems in Lake Malawi have been well documented, particularly around river mouths and in the more densely populated and shallower southern portion of the lake, where algal communities and their sedimentation rates have begun to change. Cage culture discharges may accelerate these changes.

No description available.

This study investigated hydrogen produced from feeding three types of biomass wastes (rice straw, banyan leaves, and dry algae) into the microwave plasma system. When operating the microwave plasma system atmospherically (including 12SLM of central and vortex air flow at a power of 800W, 900W, or 1000W), different feeding methods were adopted, and the researchers measured the concentration of hydrogen and other gas products, calculated the conversion rate, and evaluated the feasibility of the technique. For feeding rice straws into the microwave plasma system at 800W, 900W, and 1000W using the upstream method, the concentrations of the produced hydrogen were 47.92%, 52.66%, and 56.08%, respectively. For feeding rice straws using the downstream method, the concentrations of the produced hydrogen were 33.65%, 40.15%, and 45.39%, respectively. For feeding banyan leaves using the upstream method, the concentrations of the produced hydrogen were 40.61%, 48.63%, and 52.82%, respectively. For feeding banyan leaves using the downstream method, the concentrations of the produced hydrogen were 34.08%, 37.97%, and 40.52%, respectively. For feeding dry algae using the upstream method, the concentrations of the produced hydrogen were 36.75%, 41.34%, and 45.13%, respectively. For feeding dry algae using the downstream method, the concentrations of the produced hydrogen were 30.80%, 33.20%, and 37.58%, respectively. This data indicates that the upstream feeding method is better than the downstream one for hydrogen production, and an increase of power can enhance the production of hydrogen. The most optimum hydrogen production was achieved when rice straws were fed into the system using the upstream method at a power of 1000W; each gram of rice straws produced about 40.47mg of hydrogen (conversion rate = 67.45%). For banyan leaves and dry algae, 40.40mg (conversion rate = 67.33%) and 31.46mg (conversion rate = 52.43%) of hydrogen were produced respectively. For other gas products, no CH4 was produced in this study because most of the produced CH4 from microwave plasma conversion had reacted with CO2 and produced CO and H2. The study also revealed that the concentration of CO2 decreased as the power decreased, and this drop of concentration was more apparent in the upstream feeding method than in the downstream method. Nevertheless, the result from t-test suggested that the different CO2 concentration at different power was not statistically significant. SWOT analysis was performed to examine the feasibility of using microwave plasma atmospherically for converting biomass wastes to hydrogen, and the result revealed that internally, the emphasis should be placed on the quality and quantity of products, as well as the techniques and performance, while externally, economy, policies, and energy sources should be the focuses.

<p>Introduction. Improvement of the product flow by means of applying the lean principles, including the value stream mapping tool has become an important component in the at-tempt of many companies to make transition from traditional production to the lean manu-facturing system. It often implies modernization of organizational structure, relationships with sub-contractors, suppliers and transportation companies. The topic of this master the-sis originates from company HAGS Aneby AB that produces playing systems comprising different components. This report is an attempt to understand and analyze the problems in the product flow on the example of playing system Agito that includes Origo product fam-ily components as the main constructive part.</p><p>Purpose. The purpose of this case study has been to identify, analyze and propose solu-tions for waste-related problems in the Origo product flow, by applying the lean thinking principles and the data collection methods.</p><p>Method. The proposed case study methodology combines both theoretical and empirical approach. Data collected in interviews with sub-contractors and suppliers, and observa-tions at the mechanical workshop and warehouse, have constituted the input for the value stream mapping method. The value stream mapping method has been applied to construct the current state map of the Origo value stream and identify the wastes. Furthermore, other methods including the decision point analysis, the postponement theory, and the supplier/buyer dependence grid have been subsequently applied to analyze the company relationships with key business partners and assist in designing a draft of the future state map.</p><p>Conclusion. It has been concluded from the constructed current state map of Origo value stream that the most critical wastes are waiting, transportation, unnecessary inventory, un-necessary motion and defects. Furthermore, the requirement of minimum quantity of raw material to be purchased from the supplier and the improper workshop layout has been recognized as the main reasons for the wastes. The measures to reduce the identified wastes have been pointed out. It has been proposed to better integrate the key actors into the HAGS supply chain. Adopting the cellular layout in the mechanical workshop has been found beneficial as well as orientation of production on customer orders rather than on forecasting. The mentioned measures to reduce wastes have been summarized in the draft of the future state map. The main advantages of the proposed future state are faster order fulfillment process, gained visibility and control of raw material and reduced costs in the flow of Origo components.</p>

<p>Introduction: To improvement the target company’s manufacturing process by applyinglean principles, including using and analyzing the internal value stream mapping. Asmore and more companies have paid attention to implement lean thinking in theirmanufacturing process, the value stream mapping played an important role for manycompanies to make a transition from their traditional production systems to lean systems.The content and resources of this master thesis come from an American furniturecompany named KAMA which mainly produces office furniture with different components.Although there are various types of products, the authors merely focus on the officechair products. This research is an attempt to understand and analyze the problemsin the production flow on the example of KAMA’s office chair products that includesPH product family as the target research part.Purpose: The purpose of this research study is to investigate, analyze and find out solutionsfor waste-related problems in the office chair manufacturing flow of KAMA.Method: A single case study will be applied in this study paper. Data should be collectedfrom telephone interviews with company’s managements, the studying ofKAMA’s internal documentation and the secondary data from lean project report collectedby Consultant EIMI. In order to improve the production process, the valuestream mapping method will be applied to build the current value state map of CompanyKAMA and identify the potential wastes during the manufacturing process, andthen analyze and give the solutions for future improvement. Additional, other methodsincluding the order penetration point analysis, make-to-stock theory, and the CONWIPanalysis have been subsequently applied in designing a draft of the future state map.Conclusion: From the constructed current value stream mapping of KAMA officechair manufacturing process, it can be found that the most essential wastes are overproduction,waiting, unnecessary inventory and unnecessary movement. In addition, theimproper workstation arrangement and unnecessary waiting time have been identified asthe critical wasting reasons. Thus, any solutions to reduce or eliminate the identifiedwastes have been considered and would be given in the future state. In order to improvethe efficiency and reduce the unnecessary movements, adopting the appropriate cellularlayout in the mechanical workshop is quite beneficial. The mentioned methods to reducewastes have been summarized in the draft of the future state map of the company.The main benefits of the proposed future state value stream mapping are faster and accurateorder fulfillment process, reduction of unnecessary movements in workshop, lowinventory, high productivity and reduced costs in the flow of KAMA’s manufacturingprocess.</p>

Thesis (M.P.H.)--University of Wisconsin -- La Crosse, 2009. / Includes bibliographical references (leaves 75-77)

Thesis (Ph.D)--Earth and Atmospheric Sciences, Georgia Institute of Technology, 2010. / Committee Chair: Taillefert, Martial; Committee Member: DiChristina, Thomas; Committee Member: Sobecky, Patricia; Committee Member: Van Cappellen, Philippe; Committee Member: Webb, Samuel. Part of the SMARTech Electronic Thesis and Dissertation Collection.

M. Tech. Chemistry. / The aim of this study was to develop and evaluate an analytical method for the determination of Cr(VI) in ferrochrome dusts and to apply the method in the analysis of environmental samples (grass, soil and tree bark) for Cr(VI) content (that might be caused by dust emissions originating from the smelter). Both the public and Xstrata Wonderkop ferrochrome plant will benefit from data of Cr(VI) determination generated from the study. The information can potentially be incorporated into health risk assessments of the affected geographical areas. The results of the investigation showed that ferrochrome smelter dust emissions were the source of contamination of the environment with Cr(VI). With time, Cr(VI) could accumulate in soil to unacceptable levels, thereby endangering both plants and animals.

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Η προτεινόμενη έρευνα αποσκοπεί στην μελέτη των περιβαλλοντικών παραμέτρων του υδατικού αποδέκτη (Πατραϊκού Κόλπου) των επεξεργασμένων αστικών λυμάτων της πόλης των Πατρών. Η μελέτη περιλαμβάνει την ανάλυση και σύνθεση των εξής φυσικών και χημικών παραμέτρων του θαλασσινού νερού : 1) θερμοκρασία, 2) αλατότητα, 3) διαλυμένο οξυγόνο, 4) φωσφορικά/νιτρικά άλατα, 5) αιωρούμενο υλικό και 6) θαλάσσια ρεύματα. Οι παράμετροι αυτοί θα μετρηθούν σε συγκεκριμένο σημείο γύρω από το στόμιο του υποθαλάσσιου αγωγού. Μετά την ανάλυση των στοιχείων θα γίνει προσπάθεια να εξετασθεί η διάχυση των αποβλήτων στο θαλάσσιο χώρο με την βοήθεια αριθμητικού ομοιώματος. / -