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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 63 for “"preheating"”.
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Preheating in multifield inflation
… attractor behavior of the fields. We study preheating in multifield models of inflation with nonminimal couplings. In this phase, we find an efficient transfer of energy from the oscillating background fields to the coupled fluctuations. We identify features of preheating that are not …
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Preheating in new Higgs inflation
… with parametric resonance, the process is called preheating. New Higgs Inflation presumes that the Higgs field is the scalar field in question, involving a characteristic non-minimal "derivative" coupling. The equation of motion for the field evolves like a damped harmonic oscillator, so we expect …
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Fuel preheating in free-burning fires
Massachusetts Institute of Technology. Dept. of Chemical Engineering. Thesis. 1967. Ph.D.
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An air-preheating system for blast furnaces
Thesis: M.S., Massachusetts Institute of Technology, Department of Mechanical Engineering, 1984
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Transient model of preheating a submerged entry nozzle
Adequate preheating of the submerged entry nozzle (SEN) is important to avoid problems such as thermal cracks and skulling, and depends on torch configuration, fuel, SEN geometry and other factors. A steady-state axisymmetric computational model of the flame, combustion reactions, and air …
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High-throughput extrusion additive manufacturing using electrically resistive preheating
Extrusion-based additive manufacturing, commonly known as fused deposition modeling (FDM) or fused filament fabrication (FFF) is incredibly useful in industry for a variety of reasons, including rapid prototyping and the ability to create complex geometries easily. However, its further adoption is …
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Advancing Cold Spray for Additive Manufacturing: A Study on Particle Morphology, Gas Nature, and Particle Preheating
This investigation aims to understand and improve the deposition quality and rates of cold spray for additive manufacturing in a way that is economically sound and without the detrimental temperature effects seen in traditional metallic additive manufacturing processes. It focuses on materials that …
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A study on the effect of increased heat input on residual stress, microstructure evolution and mechanical properties in Ti6Al4V selective laser melting
… SLM machine (Low Heat Input). The effect of preheating on these properties was also studied. The low heat input specimens had two sets of test specimens, where one set was built without preheating and the other built at a preheating temperature of 200°C. This was the maximum preheating …
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Thermal Performance Comparison of Three Integrated Thermal Solar Roof Collectors
… In heating season, part of the space heating and preheating domestic hot water demand can be met by this integrated system. In the cooling season, cooling load reduction and preheating domestic hot water can be achieved by operating this system. The traditional solar thermal system is an add-on …
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Fatigue life and mechanical behaviour of aluminium alloy aa6061 chips prepared by hot extrusion process
… products were investigated under varying preheating temperatures (PHT) of 450 °C, 500 °C, 550 °C and preheating times (PHTi) of 1 hr, 2 hrs, and 3 hrs respectively. From the Design of Experiments (DOE) principle, 11 samples (S1-S11) selected were sufficient to investigate the initial …
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Aggregator-Assisted Residential Participation in Demand Response Program
… residential loads. In this work, hot water preheating and air-conditioning pre-cooling techniques are investigated with the help of developed mathematical models to find out demand response potentials of those loads. The developed water heater model is validated by comparing results of two …
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Thermosetting curing systems modeling project
… epoxy/amine system. Chapter 2 is the study on preheating impact on urethane foaming process with assistance of modeling approach. Chapter 3 is the application of further developed model in simulation of epoxy/amine curing. According to related previous work, a modeling/simulation program using …
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Determination of Stability Conditions of a Pyrometer in a Continous Production
… in battery production, especially during the preheating phase before foaming. This thesis explores the stability of pyrometers, non-contact infrared sensors, used in continuous production at BMW Group Debrecen. Inaccurate readings can lead to faulty products and increased waste. Through …
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Reducing industrial energy costs through energy efficiency measures in the South African foundry industry - evaluation and opportunities of a South African foundry
… measures included the compressed air system, preheating of the charge material and the reduction of the holding furnaces were analysed. The results of all evaluated measures, namely lighting, load-shifting and maximum demand management were cost effective solutions. Furthermore the recommended …
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ΒΕΛΤΙΣΤΟΠΟΙΗΣΗ ΤΗΣ ΕΚΧΥΛΙΣΗΣ ΛΑΤΕΡΙΤΩΝ ΜΕ ΘΕΙΙΚΟ ΟΞΥ
… TEMPERATURE, ACID CONSUMPTION, PULP DENSITY, PREHEATING OF ORE ETC ON METALS RECOVERY AND ACID CONSUMPTION WAS INVESTIGATED. THESE EXPERIMENTAL RESULTSWERE CONFIRMED BY THE CONSTRUCTION AND OPERATION OF A SMALL PILOT LEACHING PLANT FOR CONTINUOUS COCURRENT LEACHING. THE DATA GATHERED BY …
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Feasibility of an integrated biogas scrubber for a swine manure digester
… desorbed from the influent manure in an enclosed preheating vessel, the mix tank, and subsequently reabsorbed in a separate scrub tank full of water (charging cycle). The biogas was passed through this charged scrubbing solution (scrubbing cycle). The CO$\sb2$ would then be absorbed from the …
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Lean Premixed Prevaporised Combustion for Microturbines
… at ambient pressure. The results show that preheating the air to 343 and 393 K has little effect on the lean blow-off (LBO) velocity, but recessing the fuel injection significantly decreases the lean stability limit. To correlate these limits, various attempts to define a Damköhler number …
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A Heat Transfer Modeling Study of Rail Thermite Welding
… It was found that a wider weld gap, a longer preheating time, and a higher liquid temperature help to reduce the occurrence of the most severe weld defects in thermite welds. The influence of welding conditions were summarized in defect formation maps which can be used to guide the selection …
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Some Aspects of Inflationary Particle Production
… matrix. This allows us to endow the process of preheating with C and CP violation, leading to the coherent baryogenesis scenario. We present models where this mechanism is operative in the context of hybrid inflation and the grand unified theories Pati-Salam and SO(10). It is shown that a baryon …
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Single droplet combustion of alternative fuels
… combustion progresses through distinct stages: preheating, swelling, and burning. While hydrocarbon fuels exhibited swelling and followed the D² law, fuels like ethanol, methanol, and algal oil displayed micro-explosions, deviating from this behavior. Flame characteristics also varied across …
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