Master of Arts / Department of Geography / Jida Wang / Monitoring salt pans is important especially for agricultural management in arid or semi-arid regions because salt pans can negatively affect human life, wildlife, and ecology. Some of the harmful impacts of salt pans are accelerated desertification, cropland loss, economic downturn, wildlife loss, and forced migration of humans and animals due to salt storms. Spectral salt pan indices based upon remotely sensed data (using spectral properties of Landsat-8 imagery) suggested in previous studies vary by location. In other words, the spectral configuration of a salt index for a given location may not be readily applicable to another location due to spatial heterogeneity of salt components across the continental surface. Using Landsat-8 OLI imagery and climate data sets, this study aims to develop a mapping framework which can effectively extract salt pans and salt playas under various spectral conditions in different geographic locations. Based on training samples selected in eight major salt pans/playas in North America, Central Asia, Africa, and Australia, the mapping framework was designed to include the following steps: i) a conservative salt index to highlight potential salt-covered regions, ii) a calibrated support vector machine (SVM) to extract high-salinity areas in the mask regions, and iii) a posterior quality assurance/ quality control (QA/QC) with assistance of auxiliary datasets (e.g., surface slope and land covers) to eliminate commission errors and refine the extracted saltpan areas. The developed mapping framework was validated in the arid endorheic regions across the western United States, with a total area of 699 thousand square kilometers. Both qualitative and quantitative assessments of the results show reliability of the developed framework. The overall accuracy of the extracted salt pans prior to QA/QC is 97%. The final product after QA/QC achieves an overall accuracy of 99.95% and a Kappa statistic of 0.99.According to the results of salt pans areas and endorheic basins areas, it can be concluded that two aforementioned variables of this study are positively correlated to each other, and 1.10 percent of the entire case study area is covered by salt pans. The accuracy of the results suggests a potential that the mapping framework, together with the collected training sample and algorithms, may be applicable to identify salt pan and salt playa regions across the Earth’s land surface.

<p><br />U disertaciji su opisane sinteze i fizičko-hemijske karakterizacije 32 kompleksa kobalta(III), nikla(II) i bakra(II) sa ligandima S-metilizotiosemikarbazonom 2-acetilpiridina (HL&sup1;), bis(S-metilizotiosemikarbazonom) 2,6-diacetilpiridina (H₂L&sup2;), tiosemikarbazonom-S-metilizotiosemikarbazonom 2,6-diacetilpiridina (HL&sup3;), 1-adamantoilhidrazonom 2-acetilpiridina (HL⁴) i 1-adamantoilhidrazonom di(2-piridil)-ketona (HL⁵).</p><p>Kako ligandi HL&sup3;, HL⁴ i HL⁵ do sada nisu bili sintetisani, dobijeni rezultati ujedno predstavljaju i prve iz njihove koordinacione hemije. Iako je sa S-metilizotiosemikarbazonom 2-acetilpiridina poznato nekoliko kompleksa, do sada nijedan od njih nije strukturno okarakterisan, tako da su rezultati prikazani u ovoj disertaciji dali jasnu sliku o načinima koordinacije HL&sup1;. Takođe, kako je sa H₂L&sup2; poznat vrlo malo broj kompleksa, dobijeni rezultati su dali značajan doprinos razumevanju koordinacione hemije ovog liganda.</p><p>Gotovo svi sintetisani kompleksi (njih 27 od 32) su strukturno okarakterisani metodom rendgenske kristalografije. Odabrana jedinjenja su ispitana metodama termičke analize, a utvrđena je njihova antimikrobna i citotoksična aktivnost.</p><p>&nbsp;</p> / <p>This thesis describes syntheses and physico-chemical characterizations of 32 complexes of cobalt(III), nickel(II) and copper(II), with ligands 2-acetylpyridine S-methylisothiosemicarbazone (HL&sup1;), 2,6-dicetylpyridine bis(S-methylisothiosemicarbazone) (H₂L&sup2;), thiosemicarbazone-S-methylisothiosemicarbazone 2,6-dicetylpyridine (HL&sup3;), 2-acetylpyridine 1-adamantoylhydrazone (HL⁴), and di(2-pyridil)-ketone 1-adamantoylhydrazone (HL⁵).</p><p>Since the ligands HL&sup3;, HL⁴, and HL⁵ were not synthetized hitherto, the obtained results are the first regarding their coordination chemistry as well. Even though there are several complexes reported with 2-acetylpyridine S-methylisothiosemicarbazone as a ligand, none of them was structurally characterized. Therefore, here presented results gave clear insight into coordination modes of the HL&sup1;. Moreover, since there is limited number of complexes with H₂L&sup2; reported hitherto, the obtained results gave significant contribution to understanding of its coordination chemistry.</p><p>Almost each synthetized complex (27 out of 32) was structurally characterized by means of single crystal X-ray crystallography. The selected compounds were characterized by thermal analysis, and their antimicrobial and cytotoxic activity were determined.</p>