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.
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Showing 1 to 20 of 20 for “"TiCl₄"”.
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Techno-economic evaluation of demilitarized TiCl₄ recycling processes
… of demilitarized titanium tetrachloride (TiCl₄), which had been obtained by the preceding demilitarization of smoke mortars. The demilitarized TiCl₄ was quantified to be approximately 42 ton, distributed into smaller batches and processed over a period of six years. This analysis was …
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Kinetic and Microstructural Study of Titanium Nitride Deposited by Laser Chemical Vapor Deposition
The deposition apparent activation energy was calculated as 122 $\pm$ 9 kJ/mole using growth rates measured by film height and 117 $\pm$ 23 kJ/mole using growth rates measured by LIF signals. This puts the process in the surface kinetic growth regime over the temperature range 1370-1610 K. Above …
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Dinitrogen complexes of titanium and vanadium stabilized by phosphine ligands
… starting materials. The reactions of TiCl₄, TiCl₃(THF)₃, or VCl₂(TMEDA)₂ with LiN(SiMe₂CH₂PR₂)₂ (R = isopropyl or methyl) yielded the new phosphine complexes TiCl₃[N(SiMe₂CH₂PPri₂)₂] (1), TiCl₃[N(SiMe₂CH₂PMe₂)₂] (2), {TiCl₂[N(SiMe₂CH₂PPri₂)₂]}x (x = 1 or 2) (3), or …
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An investigation of the temperature distribution induced during laser chemical vapor deposition (LCVD) of titanium nitride on titanium-aluminum-vanadium
To understand how the substrate temperature influences the deposition rate and spatial profile of deposits formed using laser chemical vapor deposition (LCVD), spatially resolved multi-wavelength pyrometry measurements of the substrate temperature have been made during LCVD of titanium nitride …
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Assessment of Reorganization of Management and Performance Trends n TTCL Since 2001
TICL is a founder company of telecommunication services in Tanzania. Since its privatization on 23rd February 2001 with 35% and 65% shares distribution to Celtel International and The Government of Tanzania respectively as share holders, it has undergone two major re-organizational changes. Despite …
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"Low-valent early transition metal complexes stabilized by the chelating tripod phosphine ligand ( t-butyl)tris((dimethylphosphino)methyl);silane (""trimpsi"")"
"The organometallic chemistry of the early first-row metals has been extended through the use of a new tridentate phosphine ligand, Bu$\sp{\rm t}$Si(CH$\sb2$PMe$\sb2$)$\sb3$, or ""trimpsi"". The starting materials (trimpsi)TiCl$\sb3$(thf), (trimpsi)VCl$\sb3$(thf), (trimpsi)CrCl$\sb3$, and …
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Laser Chemical Vapor Deposition of Titanium Nitride and Process Diagnostics With Laser-Induced Fluorescence Spectroscopy
TiN films have been deposited on Ti-6Al-4V substrates by a cw CO$\sb2$ laser chemical vapor deposition (LCVD) process with TiCl$\sb4$, H$\sb2$, and N$\sb2$. Pulsed dye laser induced fluorescence (LIF) spectroscopy is used to obtain transient gas phase Ti atomic concentration above the substrate. …
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Predictive multiscale computational modeling of nanoparticles in flame reactors
<p>This dissertation details a predictive computational approach for modeling titanium dioxide</p> <p>nanoparticles in flame reactors. The industrial production of these nanoparticles is done using</p> <p>the chloride process, i.e. titanium tetrachloride (TiCl<sub>4</sub>) is oxidized in a flame to …
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Photoanode and counter electrode modification for more efficient dye sensitized solar cells
With the increasing consumption of energy and the depletion of fossil fuels, finding an alternative energy source is critical. Solar energy is one of the most promising energy sources and solar cells are the devices that convert solar radiation into electricity. Currently, the most widely used …
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The coordination and atom transfer chemistry of titanium porphyrin complexes
<p>The preparation, characterization, and reactivity of a series of ([eta][superscript]2-alkyne)(meso-tetratolylporphyrinato)titanium(II) complexes are described. Also described are intermetal oxygen atom transfer reactions involving titanium(IV) and titanium(III) porphyrin complexes. The …
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Synthesis and Reactivity of Some Organometallic Chalcogenide Complexes
Examples of Sila-1,1-dithiolate complexes, Cp$\sb2$MS$\sb2$SiMe$\sb2$ (M = Ti (8) and V) and PtS$\sb2$SiMe$\sb2$(P(C$\sb6$H$\sb5$)$\sb3$)$\sb2$, were prepared by treating (Me$\sb2$SiS)$\sb3$/Li$\sb2$S with the metal dichlorides. Compound 8 is particularly interesting because it contains two …
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Hexametalates as Catalysts for Photochemical Oxidation Reactions
The reaction of TiCl$\sb4$ with WO$\sb4$((n-C$\sb4$H$\sb9$)$\sb4$N) $\sb2$ in acetonitrile yields ClTiW$\sb5$O$\sb $ ((n-C$\sb4$H$\sb9$)$\sb4$N) $\sb3$. The complexes ROTiW$\sb5$O$\sb $ (n-C$\sb4$H$\sb9$)$\sb4$N) $\sb3$ (R = CH$\sb3$, C$\sb2$H$\sb5$, and (CH$\sb3$)$\sb2$CH) are prepared in an …
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Observation of the first titanium alkyl/alkyl complexes: The key intermediate in the Ziegler-Natta mechanism for the polymerization of alkenes
The complexes trans-TiX$\sb2$(dmpe)$\sb2$ (X = BH$\sb4,$ Br, Cl, Me, and OPh) react with alkenes to give two diamagnetic products: the mononuclear and dinuclear complexes trans-TiX$\sb2$ (alkene)(dmpe)($\eta\sp1$-dmpe) and trans- (TiX$\sb2$(alkene)(dmpe)) $\sb2(\mu$-dmpe). A crystallographic study …
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Synthesis, characterization and chemical vapor deposition of transition metal di(tert-butyl)amido compounds
… Both are EPR silent at 4.2 K. Treatment of TiCl₄ with three equivalents of LiN(t-Bu)2 in pentane affords the briding imido compound Ti₂[μ-N(t-Bu)]₂Cl₂[N(t-Bu)₂]₂ via a dealkylation reaction. Rotation around the bis(tert-butyl)amido groups is hindered, with activation parameters of ΔH‡ = 12.8 …
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The Impact of Selected Factors on Effective Advertising: the Case Study of Tanzania Telecommunications Company Limited (TTCL)
This study examined the impact of selected factors on effective advertising in Tanzania Telecommunications Company Limited with the view that this might be applicable to other organizations as well. The specific objectives of the study were to determine budget allocation and spending and its impact …
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Correct Programs, Executed Correctly: Verifying Specifications And Executions
Computer programs control vital infrastructure, safeguard national security, and process all financialtransactions, making their correctness and security paramount. Formal verification is a key tool for program trust and assurance. However, as the complexity of computer systems grows, the …
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Synthetic and structural studies on early transition metal siloxides
[Super- and subscripts in abstract] n-Bu3SiOH was prepared from both n-Bu3SiH and n-Bu3SiCI. Reactions of n-Bu3SiOH with NaH, LiBun, MC15 (M = Ta or Mo) and Cp2MCl2 (Cp = 115-C5H5, M = Ti or Zr) were investigated, in some cases using the base Et3N as a hydrogen chloride acceptor. Na+(QSiPh3r was …
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THE STUDY AND CHARACTERIZATION OF A NEW PROCEDURE FOR APPLYING CARBIDE COATINGS TO GRAPHITE FURNACES USED IN ATOMIC ABSORPTION SPECTROSCOPY
<p>The object of this dissertation is the study and characterization of a new method for applying carbide coatings to graphite furnaces used in atomic absorption spectroscopy. The proposed method consists of impregnating graphite furnaces, under reduced pressure, with a liquid metal chloride. After …
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New chelating ligands: Applications to hydrodenitrogenation catalysis
The reaction of (DIPP)₂TaCl₃(Et₂O) (6, DIPP = 2,6-(CH(CH₃)₂C₆H₃O-)) with two equivalents of 3,5-lutidine and two equivalents of Na/Hg yields the cyclometallated product (DIPP')(DIPP)TaCl(3,5-lutidine)₂ (8) in which one of the isopropyl groups on a DIPP ligand is activated to form a …
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Antecedentes, dinâmica e consequentes do desenvolvimento vocacional na infância
Actualmente, o desenvolvimento vocacional é caracterizado como um processo de ciclo-vital, influenciado por factores pessoais e contextuais. Não obstante ser evidente que as bases da exploração e da aprendizagem vocacional se formam durante a infância, são escassos os estudos que focam os primeiros …