Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 31 for “"Exothermic reaction"”.
-
The effects of natural convection on low temperature combustion
When a gas undergoes an exothermic reaction in a closed vessel, spatial temperature gradients can develop. If these gradients become sufficiently large, the resulting buoyancy forces will move the gas, i.e. there is natural convection. The nature of the resulting flow is determined by the Rayleigh …
-
Asymmetric temperature and composition profiles in catalyst particles
In the many published discussions of chemical reactions accompanied by heat conduction and diffusion in catalyst particles, it has been tacitly assumed that the temperature and concentration profiles have the symmetry of the particle. It is the main purpose of this work to show that this is not …
-
Materials development for multicomponent systems with variable oxidation states
… (cation:organic ratio), characteristics of the exothermic reaction (C/N ratio), calcination/crystallization atmosphere and temperature, were investigated. Additionally, the electrochemical performance of the LiMn2O4 (LMO4) composition was evaluated and compared against commercial LiMn2O4 …
-
Modelling spherical flame propagation in a closed volume
The highly exothermic reaction of fuel combustion is the most common source of usable energy in the world. The fuel itself originates almost entirely from fossil fuels, such as crude oil and natural gas. The use of these fuels for energy production is under pressure in recent times due to …
-
Zirconium alloy getter bed air-ingress thermal failure analysis
… of air into a packed St-909 getter bed, the exothermic reaction of oxygen and pellet material pushes temperatures within the bed to extremely high levels. This failure mode, which could be caused by a line rupture, was modeled, analyzed, and a full-scale experiment was performed in the …
-
Methodology for Pyrolysis-induced Thermal Runaway Analysis in Li-ion Batteries
… electrolytes displayed a pronounced exothermic peak at 350°C, indicative of significant decomposition reactions. In contrast, the LiFSI-ether electrolyte exhibited an exothermic reaction at 210°C, followed by an endothermic event near 300°C. Such variances in thermal behavior …
-
Exploration of the Endothermic and Exothermic Reactions of Calcium Oxide and Magnesium Oxide and Design of a Vessel for a Thermochemical Heat Storage System
… involved in the TES system is a thermochemical reaction involving metal oxides such the calcium oxide (CaO) or magnesium oxide (MgO) and water. In the output mode, an exothermic reaction is initiated when liquid water or steam is injected into the metal oxide particle bed to produce Ca(OH)2 or …
-
Development and Scale-Up of ‘The Bradford Process’ for the Production of Titanium and Titanium Alloys
… scalability, alloy/part production potential, reaction mechanism and general process improvement. The research was primarily undertaken using laboratory grade Anatase Phase TiO2, Acetone, Distilled Water and HCl and evaluated via controlled partial/full reduction reactions. With analysis …
-
Development of High Strength Dicalcium Phosphate Anhydrous Cement with Nanosilica Sol
… of DCPA generally utilizes a high temperature exothermic reaction which is difficult to repeat and control as well as having to set before implantation in the human body. A diverse range of materials and fibers have been added to Dicalcium Phosphate Anhydrous Cements to act as reinforcements to …
-
Investigating Energetic Porous Silicon as a Solid Propellant Micro-Thruster
… thrust and impulse produced during the exothermic reaction as a function of porosity. The baseline porous silicon devices were two millimeter diameter and etched to a target depth of 25 microns. As a result of changing porosity, a 7x increase in thrust performance and a 16x increase in …
-
Control strategies for exothermic batch and fed-batch processes A sub-optimal strategy is developed which combines fast response with a chosen control signal safety margin. Design procedures are described and results compared with conventional control.
… scope for improving the temperature control of exothermic processes. In this thesis, a sub-optimal control strategy is developed through utilizing the dynamic, simulation tool. This scheme is built around easily obtained knowledge of the system and still retains flexibility. It can be applied to …
-
Evaluation of a Strut-Plasma Torch Combination as a Supersonic Igniter-Flameholder
… work were the following: 1. Tests showed that an exothermic reaction takes place. 2. The amount of heat release increases with an increase in the mass flow rate of fuel. 3. The plasma torch-fuel injector interaction caused the heat release to be well above the tunnel floor and sometimes off the …
-
ADAPTIVE TUNING OF A PID CONTROLLER USING NEURAL NETWORKS
… stirred tank reactor where an irreversible exothermic reaction is carried out in a perfectly mixed reactor. PID (Proportional, Integral, and Derivative) controllers have been the most popular controllers in the chemical industry. Several studies focused on adaptively tuning the PID gains. In …
-
Development of a sulfate reducing packed bed bioreactor for use in a sustainable hydrogen production process
… its subsequent overall conversion to H2 via an exothermic reaction. The current study examined the first step of this process, namely, the design and operation of a packed bed bioreactor with high volumetric H2S production (mol/m3.d) and its comparison to analogous methanogenic technology. A …
-
Scale-up and optimisation of the β-chloroacrylamide process by batch and continuous flow methods
… to produce the starting material for the cascade reaction (third step). It addresses the issues associated with scaling-up a highly exothermic reaction in the first step and poor reaction efficiency and impurity management in the second step. This work effectively utilises both continuous flow and …
-
Al-Ni Nanofilm Powered Miniature Linear Actuator for Medical Devices
… to cycle a piston in a drug loaded cylinder. Via exothermic reaction, nanofilm deposits thermal energy into the alcohol filled pressure vessel in order to generate the pressure needed to perform a jet injection. Cylindrical pressure vessel chambers with a diameter of 7mm and heights ranging from …
-
First-principles modeling of thermal stability and morphology control of cathode materials in Li-ion batteries
… the energy of a large number of oxidation reactions of 3d transition metal oxides using the generalized gradient approximation (GGA) to density functional theory and GGA+ U method. Two substantial contributions to the error in GGA oxidation energies are identified. The first contribution …
-
The Fate of Flame Volatized Sodium During the Combustion of Pulverized Coal in Reaction With Silica and Sulfur (Studied with the Aid of a Synthetic Coal)
… 1.4 seconds. As well as studying the inorganic reactions, a detailed look was also spent on the actual combustion characteristics of the synthetic coal. These results are serendipitous in nature but deserve attention as well.</p> <p>The addition of a carbon matrix to a model mixture alters the …
-
Mechanisms In the Water Vapor Hydrolysis of Sodium Borohydride
… (NaBH<sub>4</sub>), release hydrogen via exothermic reaction with water as follows: NaBH<sub>4</sub> + (2+x) H<sub>2</sub>O → 4H<sub>2</sub> + NaBO<sub>2</sub>·xH<sub>2</sub>O + heat. The gravimetric and volumetric capacities of NaBH<sub>4</sub> combined with its relatively low …
-
High temperature steam oxidation of titanium-coated Zircaloy-2 and Titanium-Zirconium Alloys
… reduction of hydrogen gas production due to the exothermic reaction of high temperature steam and the Zircaloy fuel cladding within the reactor during a Loss-of -Coolant Accident (LOCA). The hydrogen, which collected in the reactor vessel and containment buildings, caused devastating hydrogen gas …
Page 1 of 2