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Showing result 21 - 25 of 434 essays matching the above criteria.

  1. 21. Thermodynamic modelling of the copper-zinc-tin ternary system : A study towards lead-free brass

    University essay from KTH/Materialvetenskap

    Author : Caterina Radogna; [2023]
    Keywords : Brass-based alloys; Lead-free brass; Calphad; Thermo-Calc; Thermodynamic description; Mässingsbaserade legeringar; Blyfri mässing; Calphad; Thermo-Calc; Termodynamisk beskrivning;

    Abstract : Lead (Pb) is frequently used as an alloying element in brass to enhance machinability and castability. However, this element poses a significant risk to human health and the environment. The 2021 revision of the Drinking Water Directive imposed stricter limits on Pb content in brass, encouraging the development of lead-free brass. READ MORE

  3. 22. Forecasting copper price using VAR and the XGBoost model: an experiment with a relatively small dataset

    University essay from Lunds universitet/Nationalekonomiska institutionen; Lunds universitet/Statistiska institutionen

    Author : Juanli Hu; [2023]
    Keywords : copper price; Vector autoregressive model; XGBoost; Time series; Business and Economics;

    Abstract : Given the importance of copper prices to investors, governments, and policymakers, this paper investigates short-term price predictability using VAR and XGBoost models. All models are trained with historical data from November 2021 to December 2022 and using MSE, RMSE and MAE for evaluating the model performance. READ MORE

  4. 23. In situ electrokinetic remediation of soil co-contaminated with trace elements and polycyclic aromatic hydrocarbons

    University essay from Luleå tekniska universitet/Institutionen för samhällsbyggnad och naturresurser

    Author : Emma Heidrich; [2023]
    Keywords : polycyclic aromatic hydrocarbons; trace elements; co-contaminated soil; electrokinetic remediation; iron electrodes;

    Abstract : Sites contaminated with polycyclic aromatic hydrocarbons can be simultaneously contaminated with trace elements. Co-contaminated soil is considered a complex problem since inorganic and organic contaminants behave differently and thereby often require different remediation strategies. READ MORE

  5. 24. A Petrographic and Paragenetic Characterization of the Ertelien Ni-Cu Deposit (Norway)

    University essay from Uppsala universitet/Institutionen för geovetenskaper

    Author : Alena Niarezka; [2023]
    Keywords : Ertelien Ni-Cu deposit; ore geology; enrichment processes; nickel; cobalt; copper; optical microscopy; electron probe micro-analysis; critical metals; Ertelien Ni-Cu fyndighet; malmgeologi; anrikningsprocesser; nickel; kobolt; koppar; optisk mikroskopi; elektronsondsmikroanalys; kritiska metaller;

    Abstract : The escalating demand for metals driven by advancements in renewable energy technologies and hightech products has underscored the significance of understanding and characterizing ore deposits. This study focuses on the Ertelien Ni-Cu deposit in Norway, a region rich in nickel, cobalt, and copper resources—essential components for the transition to a sustainable energy future. READ MORE

  6. 25. Isocyanates formation from thermal degradation of polyurethane foam during welding of district heating pipes

    University essay from KTH/Ergonomi

    Author : Muhammad Akram; [2023]
    Keywords : Polyurethane; Isocyanates; District Heating Pipes; Oxy-fuel Welding; Manual Metal Arc Welding;

    Abstract : Polyurethane insulation foam, which is used as insulation on district heating steel and copper pipes, is made from polymerisation of polyol and diisocyanates monomers. Installation of new district heating pipes or replacement of old pipes involves masses of welding activities. READ MORE