Sökning: "niobium"
Visar resultat 1 - 5 av 24 uppsatser innehållade ordet niobium.
1. Preliminary Design of a 30 kN Methane-Oxygen-powered Electric-Pump-fed Liquid Rocket Propulsion System
Master-uppsats, Luleå tekniska universitet/RymdteknikSammanfattning : The design of a liquid rocket propulsion system, unlike that of a standalone system, is intertwined with the overall development of a number of associated systems and is influenced by a multitude of conditions and considerations: from the requirements needed to accomplish the mission to the rationalizations involved behind the development of each rocket system and/or component. In my thesis, the preliminary design of a “new generation” 30 kN rocket engine driven by an electric pump feed system and running on liquid methane and liquid oxygen is performed. LÄS MER
2. Tuning Photovoltaic Properties of Two-dimensional Molybdenum Disulfide by Alloying: An ab initio study
Master-uppsats, KTH/MaterialvetenskapSammanfattning : Addressing the urgent need for innovative energy solutions amidst increasing environmental concerns, the focus on photovoltaic solar cells is intensifying. Currently limited by the Shockley-Queisser limit, conventional silicon-based solar cells offer a maximum power conversion efficiency of 32%. LÄS MER
3. Investigation of high temperature stability of additive manufactured austenitic stainless steels for space applications
Uppsats för yrkesexamina på avancerad nivå, Luleå tekniska universitet/MaterialvetenskapSammanfattning : Additive manufacturing (AM) techniques are being studied for their application in the aerospace industry. Numerous benefits come from the already in shape final piece, which needs reduced amount of prime material for its production and can have its shape numerically optimized for weight reduction. LÄS MER
4. Niobium Ohmic Contacts for Cryogenic Indium Phosphide High-Electron-Mobility Transistors
Master-uppsats, KTH/Tillämpad fysikSammanfattning : Ohmic contacts are crucial components in semiconductor devices such as transistors and diodes, and lowering their contact resistance is an important factor in device performance enhancement. This is especially important for low-noise amplifiers (LNAs) where device noise temperature decreases both directly and indirectly with decreasing contact resistance. LÄS MER
5. Correlation Between Microstructural And Mechanical Properties In Niobium Carbide Reinforced Hadfield Steel Composites
Master-uppsats, Lunds universitet/Industriell ProduktionSammanfattning : Degradation of tools is a prevalent aspect in the mechanical world; due to the advancement of technologies and intense research and development, there are new ways and ideas to curb or delay the tool failures; one such idea is to implement Metal Matrix Composites (MMCs) with various reinforcement materials. This thesis focuses on improving the hardness and wear resistance of Hadfield steel by reinforcing it with Niobium Carbide (NbC). LÄS MER