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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Hexary System of Oceanic Salts – Polythermal Pitzer Dataset (numerical supplement)

Voigt, Wolfgang 20 April 2022 (has links)
For the polythermal Pitzer dataset of the hexary system of oceanic salts (Na+, K+, Mg+2, Ca+2, Cl-, SO4-2 - H2O) including acids and hydroxides the data selection is documented in detail in the report “THEREDA - Thermodynamische Referenzdatenbasis” (Altmaier et al. 2011, https://www.grs.de/de/aktuelles/publikationen/grs-265-thereda-thermodynamische-referenzdatenbasis-abschlussbericht). The present short communication supplements this report by the numerical values of all temperature coefficients.
32

<b>AN INVESTIGATION INTO THE EFFECT OF LIGAND STRUCTURE ON CATALYTIC ACTIVITY IN WATER OXIDATION CATALYSIS MECHANISMS</b>

Gabriel S Bury (18403716) 20 April 2024 (has links)
<p dir="ltr">Insights from research into the natural photosynthetic processes are applied to inform the rational design of inorganic catalysts. The study of these synthetic systems – artificial photosynthesis – will lead towards the development of a device able to absorb light, convert and store the energy in the form of chemical bonds. The water-splitting reaction, a bottleneck of the photosynthetic process, is a key barrier to overcome in this endeavor. Thus, the focused study of water-oxidation catalysts able to facilitate this difficult reaction is performed, in order to develop a green-energy solution in the form of an artificial photosynthesis system.</p>
33

COMBUSTION CHARACTERISTICS OF ADDITIVELY MANUFACTURED GUN PROPELLANTS

Aaron Afriat (10732359) 05 May 2021 (has links)
<p>Additive manufacturing of gun propellants is an emerging and promising field which addresses the limitations of conventional manufacturing techniques. Gun propellants are manufactured using wetted extrusion, which uses volatile solvents and dies of limited and constant geometries. On the other hand, additive techniques are faced with the challenges of maintaining the gun propellant’s energetic content as well as its structural integrity during high pressure combustion. The work presented in this thesis demonstrates the feasibility of producing functioning gun propellant grains using vibration-assisted 3D printing, a novel method which has been shown to extrude extremely viscous materials such as clays and propellant pastes. At first, the technique is compared to screw-driven additive methods which have been used in printing gun propellant pastes with slightly lower energetic content. In chapter two, diethylene glycol dinitrate (DEGDN), a highly energetic plasticizer, was investigated due to its potential to replace nitroglycerin in double base propellants with high nitroglycerin content. A novel isoconversional method was applied to analyze its decomposition kinetics. The ignition and lifetime values of diethylene glycol dinitrate were obtained using the new isoconversional method, in order to assess the safety of using the plasticizer in a modified double base propellant. In chapter three, a modified double base propellant (M8D) containing DEGDN was additively manufactured using VAP. The printed strands had little to no porosity, and their density was nearly equal to the theoretical maximum density of the mixture. The strands were burned at high pressures in a Crawford bomb and the burning was visualized using high speed cameras. The burning rate equation as a function of the M8D propellant as a function of pressure was obtained. Overall, this work shows that VAP is capable of printing highly energetic gun propellants with low solvent content, low porosity, with high printing speeds, and which have consistent burning characteristics at high pressures. </p>
34

Thermodynamic database for Pb and its compounds - data selection

Moog, Helge 25 August 2022 (has links)
This report documents the selection of thermodynamic data for lead and lead compounds. Except for elemental lead, it is restricted to lead in the oxidation state +II (plumbous lead). Besides formation constants and, in part, enthalpies of formation and standard entropies, interaction coefficients for the correction of activity coefficients following the Pitzer formalism are provided. Aqueous complexes of lead with chloride, sulphate, and hydroxide are explicitly accounted for in the Pitzer model. Wherever possible, the validity of selected data is tested by recalculating experimental data. The presented data set is valid for 298.15K only.

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