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Halogen-element (F, Cl, and Br) behaviour in apatites, scapolite, and sodalite : an experimental investigation with field applicationsDong, Ping 15 September 2005 (has links)
This is the first systematic experimental investigation of partitioning of Br between apatites and coexisting melts and the uptake of Br by scapolite and sodalite. Twenty-nine partitioning experiments between fluorapatite (FAP) /chlorapatite (ClAP) and coexisting melts were conducted in the system of CaO-P2O5-CaF2-CaCl2NaBr at 1120 degree C to 1400 degree C and atmospheric pressure. The partition coefficients (D) with errors of 1 sigma in parentheses are as follow: <p>DF (ClAP/melt) 3.59(64) at 1120 degree C to 4.13(22) at 1330 degree C <p> DF (FAP/melt) 1.05(4) at 1220 degree C to 1.07 at 1400 degree C <p> DCl (ClAP/melt) 1.07(1) at 1120 degree C to 0.83 at 1330 degree C <p> DCl (FAP/melt) 0.127(2) at 1250 degree C to 0.115 at 1400 degree C <p> DBr (ClAP/melt) 0.32(9) at 1120 degree C to 0.42(5) at 1330 degree C <p> DBr (FAP/melt) 0.020(3) at 1220 degree C to 0.016 at 1400 degree C <p> Seven exchange experiments at one atmospheric pressure and 800 to 1000 degree C yield the following distribution coefficients for Br-Cl exchanges between marialitic scapolite or sodalite and coexisting hydrous NaCl-NaBr melts: KD (marialite-melt) = 0.92 +/- 0.10 and KD (sodalite-melt) = 1.18 +/- 0.10. Therefore, the Cl/Br values in marialitic scapolite and sodalite closely reflect the halogen proportions of their coexisting melts or fluids. <p> The second part of this thesis project analyzes the halogen (F, Cl, Br) contents in natural fluorapatite and scapolite by X-ray fluorescence microprobe (XRF) for Br and electron microprobe (EMPA) for other elements. All selected localities and environments are interesting, because the origins of the parental fluids/melts are controversial. The halogen compositions of 29 natural apatite grains from the Aoshan fluorapatite-magnetite deposit (China), the Oka carbonatite complex (Quebec), and Chinese mantle xenoliths and 36 scapolite samples from the Tieshan Fe-Cu skarn deposit (China), the Nickel Plate gold deposit (British Columbia), and the Grenville pegmatite/skarn/vein deposits (Ontario and Quebec) have been analyzed by electron microprobe (EMPA) and X-ray fluorescence microprobe (XRF). Twenty six whole-rock samples from the Aoshan deposit have also been analyzed by XRF for major and trace elements. <p> Fluorapatite from the Aoshan fluorapatite-magnetite deposit is Cl-bearing with 0.38-0.98 wt% Cl, 1.83-3.45 wt% F, and 0-52 ppm Br. Fluorapatite from Chinese mantle xenoliths has similar halogen compositions to the Aoshan fluorapatite. Fluorapatite from the Oka carbonatite has trace amounts of chlorine (up to 0.052 wt%) and bromine (from 9 to 57 ppm). Applications for the experimental results suggest that the Aoshan Fe-Cu deposit has Cl/Br values comparable to those of mantle sources and that the anomalously low Cl/Br values in Oka fluorapatite require Br-enriched sources. <p> The Cl/Br values (weight) of marialitic scapolite from the Tieshan Fe-Cu deposit cluster around 626 +/- 92, supporting an origin involving hydrothermal brines from associated evaporites. Scapolite-group minerals in the exoskarns of the Nickel Plate Au skarn deposit have Cl/Br from 560 to 570, higher than those (110 to 180) of their counterparts in the endoskarns and vuggy cavities. This variation is attributable to an increased involvement of magmatic water from distal to proximal zones. Similarly, scapolite-group minerals in the Grenvillian U-Th-Mo-REE pegmatite-skarn-vein deposits vary widely in Cl/Br from 80 to 380, indicative of mixed sources of hydrothermal fluids from magmatic sources and from associated sedimentary rocks. <p> The experimentally determined partition coefficients of halogens between minerals (apatites, scapolite, and sodalite) and fluids/melts of this study have wide applications in the interpretation of source and evolution of hydrothermal fluids in mineralization processes and other geological systems. Applications of those partition coefficients to selected mineral deposits and mantle xenoliths confirm their significance.
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Spectroscopic, kinetic and synthetic studies on some of the first row transition metal halocarbonyls and their derivatives.Spendjian, Hagop Krikor. January 1970 (has links)
No description available.
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Laser flash photolysis studies of some halogen monoxide reactions of atmospheric interestCronkhite, Jeffrey M. 12 1900 (has links)
No description available.
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Aspects of non-adiabatic molecular collision theoryGover, M. R. January 1978 (has links)
This thesis is concerned with non-adiabatic effects in alkali/halogen collision systems. After a general survey of non-adiabatic molecular collision theory, and its application to such systems, calculations have been performed relating to three topics : (i) Vibrational energy distributions resulting from electron transfer collisions between alkali metal atoms and halogen molecules are often treated by the multi-curve crossing approach to the classical path approximation, in the form of two approximations, one valid at high collision energy, the other at low energy; the performance of these is evaluated over a wide energy range by comparison with the results from an "exact" multi-curve crossing approach. (ii) Classical trajectory calculations for reactive alkali / halogen collisions are performed using a simple ionic potential energy surface, developed earlier to model the weakening of the halogen bond by the metal ion immediately after the electron transfer. Detailed comparison is made between the results and those from experiment; good agreement is obtained for K/I<sub>2</sub> and comparison of the results for K/I<sub>2</sub> and Cs/I<sub>2</sub> indicates that this effect is not merely dependent on the charge of the ion. (iii) The population of ground and excited sodium atoms resulting from Na/I charge neutralisation collisions is investigated using the multi-curve crossing approach. Although it has been suggested that population inversions may be produced by such a process, it is shown that this is only possible at extremely high collision energies.
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Electrochemical reduction of fluorinated systems and derived chemistryBriscoe, Mark William January 1989 (has links)
The work described in this thesis is divided into four sections: 1. The electrochemical reduction of fluorocarbon derivatives has been investigated. A number of systems have been studied analytically (using cyclic volt amine try) ; whilst preparatively a range of compounds have been synthesised, including semi-conducting polymers and four-membered perfluorocyclic products. 2. The use of sodium amalgam as an electromimetic medium to facilitate reduction of various fluorocarbon substrates has been studied. A series of volatile cyclic and acyclic F-dienes have been prepared from F-alkenes in good yield and conversion. The chemistry of these F-dienes is then described: 3. Both mono- and bi- functional nucleophiles have been reacted, giving a range of novel substitution products. 4. A number of free radical and cycloaddition reactions have been attempted without success. However, the complexation of decamethylferrocene as a metallocene one electron donor, with various F-alkenes of low reduction potential, has allowed a radical anion of a perfluorocyclic-diene to be stabilized and fully characterized for the first time.
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Condensations by means of halogen acids ...Pantsios, Athan Anastasov, January 1941 (has links)
Thesis (Ph. D.)--University of Chicago, 1938. / Reproduced from type-written copy. "Private edition, distributed by the University of Chicago libraries, Chicago, Illinois." eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
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Elektrokinese der zilverhalogenidenJulien, Paul Frédéric Joseph Alphonse, January 1933 (has links)
Thesis (proefschrift)--Rijksuniversiteit te Utrecht, 1933. / "Stellingen" (2 leaves) inserted. Includes bibliographical references.
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Acao do propiltiouracil e perclorato de potassio sobre alguns parametros da funcao tireoidiana do rato (estudo realizado com o emprego do I-125)SUGAVARA, SUEMI 09 October 2014 (has links)
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Sintese e marcacao de 19-iodocolesterol sup(131)IHAMADA, ELENA S. 09 October 2014 (has links)
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Estudo comparativo in vitro da capacidade adesiva da resina fotoativada pela luz halogena e por laser de argonio, utilizando-se brackets metalicos em pre-molares humanosCARILLO, VITORIA E.B. 09 October 2014 (has links)
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