Martian magmas are thought to be rich in chlorine compared with their terrestrial counterparts. Consistent with other Martian meteorites, apatite grains in Martian meteorite NWA 6234 are dominantly Cl-apatite suggesting that the parental magma to NWA 6234 may have been rich in Cl. Here we experimentally investigate the effect of chlorine on liquidus depression and near liquidus crystallization of a synthetic composition of NWA 6234 and compare these results with previous experimental results on the effect of chlorine on near-liquidus crystallization of surface basalts Humphrey and Fastball. Previous experimental results using two different starting synthetic Martian basalt compositions showed that the change of liquidus temperature is dependent on the bulk composition of the basalt. The effect of Cl on liquidus depression is greater for lower SiO2, higher Al2O3 magmas than higher SiO2, lower Al2O3 magmas. The bulk composition for this study has lower Al2O3 and high FeO contents than previous work; therefore, we can further constrain the effect of the bulk composition on the influence of chlorine on near-liquidus crystallization. High pressure and temperature crystallization experiments were performed at 1 GPa (10 Kbar) on a synthetic basalt, of the bulk composition of NWA 6234, with 0 - 4 wt% Cl added to the sample as AgCl. The results are consistent with previous notions that with increasing wt. % Cl in the melt, the crystallization temperature decreases. Importantly, our results have a liquidus depression ∆T (oC) from added chlorine that is intermediate between the two previous results, consistent with the difference in bulk composition. This suggests that the addition of Cl to the Martian mantle may lower the magma genesis temperature and potentially aid in the petrogenesis of Martian magmas.

ClN_3 was photolyzed in various gas mixtures to transform its chemical energy into laser radiation. Reaction mechanisms, energy distribution in reaction products, and relative reaction rates were deduced from the laser emission. Flash photolysis of ClN_3-H_2 mixtures produced HCl laser emission; however, due to a narrow range of operating conditions and many competing reactions, the laser output was less than that obtained from comparable Cl_2-H_2 mixtures. The rate constants for H + ClN_3 —> HCl* (v=n) + N_3 were determined to be 0.45 ± 0.05 of the corresponding rate constants for H + Cl_2 —> HCl* (v=n) + Cl. Chlorine azide was examined as a source of excited N_2 (v>0) in a CO_2 laser system. Collisions of ground state CO_2 with Cl_2 (v>0) and M* prevented population inversion. The explosion of ClN_3 was used to drive an HF chemical laser by thermally dissociating NF_3 or SF_6 to produce F for the F + H_2 —> HF*+ H reaction. At high pressures laser emission was parasitized by isotropic supperadiance. The energy output was dependent on the rate of energy deposition from both flash lamp and ClN_3 explosion.

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Thesis (Ph. D.)--University of Washington, 2000. / Vita. Includes bibliographical references (leaves 161-171).

Thesis (Ph.D.) -- McMaster University, 2001. / Includes bibliographical references (leaves 237-281). Also available via World Wide Web.

The expected concentration of chlorine in the biotite fraction was not found. The chlorine was not significantly water leachable from the whole rock samples following normal grinding. The Idaho Batholith as a source for mineralizing chlorine was not established. The chlorine distribution supports, but does not prove, a metamorphic origin for the Idaho Batholith. Cretaceous and possibly tertiary thermal events may have homogenized the chlorine in the batholith. Since chlorine seems to be so widely available in source rocks, a better way to correlate its presence to mineralization would be to study the residual chlorine from the ore deposition process.

Mycobacterium avium, an opportunistic human pathogen, infects between 25 and 50% of advanced-stage acquired immuno-deficiency syndrome (AIDS) patients in the United States. M. avium has been isolated from many environmental sources including: natural waters, soils, and aerosols. M. avium has also been recovered from within municipal and hospital drinking water systems. Rhesus macaques (Macaca mulatta) infected with the simian HIV analog, SIV, have been shown to acquire M. avium infections from potable water. Reduced-aggregate fractions (cell suspensions free of large aggregates) of Mycobacterium avium were exposed to chlorine, monochloramine, chlorine dioxide, and ozone and kinetics of disinfection measured. Chlorine disinfection kinetics was also measured in M. avium cultures grown in biofilms. M. avium exhibited a high resistance to chlorine compared to E. coli. M. avium CT99.9% (disinfectant concentration x time to 3 logs cell inactivation) values were between 571- and 2318 -times those of E. coli. Clinical isolates of M. avium showed 0.24 and 2.5-fold increase in resistance to chlorine compared to their pulsed-field-gel-electrophoresis- (PFGE) matched environmental isolates. M. avium strains exhibited a mixed response to exposure to monochloramine. The CT99.9% values of three strains (2 clinical, 1 environmental) were between 6.3- and 23.5- times that of E. coli. Two strains (1 clinical, 1 environmental) exhibited CT99.9% values approximately the same as E. coli, a difference from all the other disinfectants which were much less effective on M. avium than on E. coli. M. avium strains exhibited a high resistance to chlorine dioxide when compared to E.coli. M. avium CT99.9% values of between 133- and 706- times higher that that of E. coli. In the paired isolates tested, the clinical isolate was 5.3 times more resistant than the matched environmental isolate. M. avium exhibited a high resistance to ozone when compared to E. coli. M. avium strains exhibited a CT99.9% value of between 52 and 90 times higher that that of E. coli. In the paired isolates tested, the clinical isolate was nearly identical as judged by CT99.9% values. M. avium strain 5002 exhibited an unusual disinfection kinetics curve. Disinfection rate increased by a non-logarithmic factor, indicating that inactivation efficiency was increasing over time. M. avium strain 1060 showed between a 17% decrease to a 265% increase in CT99.9% value when grown as biofilms as opposed to suspension. Due to the large variance in biofilm density and and CT99.9% values, any conclusions based on these experiments should be considered tentative at best. M. avium's resistance to chlorine and chlorine dioxide approaches that of the protozoan cysts of Giardia muris and Entamoeba hystolytica. M. avium is much less resistant, relatively, to monochloramine possessing values similar to E. coli. Ozone resistance of M. avium is two orders of magnitude greater than E. coli and one order of magnitude of less than G. muris cysts. A critical concentration threshold level for chlorine dioxide was found. That is, there was no linear relationship between concentration of chlorine dioxide and cell inactivation. Initial experiments using a range of concentrations from 0.1 ppm to 0.5 ppm chlorine dioxide showed a biphasic curve with the inflection point (indicating the critical concentration) between 0.3 and 0.4 ppm chlorine dioxide. / Master of Science

MSc (Med), Clinical Microbiology and Infectious Diseases, Faculty of Health Sciences, University of the Witwatersrand / The goal of infection control is to minimize the risk of exposure to potential pathogens and to create a safe working environment in which patients can be treated. Use of disinfectants in is an integral part of infection control. The rate of killing of microorganisms depends upon the type, concentration and time of exposure of the killing agent (disinfectant). Chlorinated compounds are frequently used in healthcare settings but chlorine dioxide has only been used in industries on a large scale. Aseptrol® is newly developed slow release chlorine dioxide and noncorrosive formula which can be used on a smaller scale basis. This study assessed the antimicrobial properties of Aseptrol® (48ppm and 24ppm) in comparison with previously used sodium dichloroisocyanurate containing formula, Presept® (10 000ppm). Both disinfectants killed more susceptible bacteria, such as Staphylococcus aureus, Pseudomonas. aeruginosa and Streptococcus mutans within 30 seconds and proved to be fungicidal by killing Candida albicans within 30 seconds. Aseptrol® and Presept® killed less susceptible mycobacteria such as Mycobacterium tuberculosis, Mycobacterium avium subsp. avium and blood borne organism Hepatitis B virus within 30 seconds. Highly resistant B. subtilis spores were killed in 2 and 2.5 minutes by Aseptrol® and Presept® respectively. Although manufacturers recommend that the disinfectant solutions should be prepared daily, when the shelf-life of prepared solutions stored in screw cap bottles was studied, the results showed that Aseptrol® can be effectively used for 27 day and Presept® for more than 37 days. The goal of infection control is to minimize the risk of exposure to potential pathogens and to create a safe working environment in which patients can be treated. Use of disinfectants in is an integral part of infection control. The rate of killing of microorganisms depends upon the type, concentration and time of exposure of the killing agent (disinfectant). Chlorinated compounds are frequently used in healthcare settings but chlorine dioxide has only been used in industries on a large scale. Aseptrol® is newly developed slow release chlorine dioxide and noncorrosive formula which can be used on a smaller scale basis. This study assessed the antimicrobial properties of Aseptrol® (48ppm and 24ppm) in comparison with previously used sodium dichloroisocyanurate containing formula, Presept® (10 000ppm). Both disinfectants killed more susceptible bacteria, such as Staphylococcus aureus, Pseudomonas. aeruginosa and Streptococcus mutans within 30 seconds and proved to be fungicidal by killing Candida albicans within 30 seconds. Aseptrol® and Presept® killed less susceptible mycobacteria such as Mycobacterium tuberculosis, Mycobacterium avium subsp. avium and blood borne organism Hepatitis B virus within 30 seconds. Highly resistant B. subtilis spores were killed in 2 and 2.5 minutes by Aseptrol® and Presept® respectively. Although manufacturers recommend that the disinfectant solutions should be prepared daily, when the shelf-life of prepared solutions stored in screw cap bottles was studied, the results showed that Aseptrol® can be effectively used for 27 day and Presept® for more than 37 days. Chlorinated disinfectants, such as Aseptrol® and Presept®, have potential to be used as intermediate to high level disinfectants in medical and dental settings, where above test organisms are primary contaminants. It is also possible to use them as sterilants, where semicritical conditions are required. Aseptrol® has an additional advantage because it is noncorrosive and can be used on metal instruments.