A hypothesis for the geochemical anomaly in the North Creek Watershed /

A regional geochemical reconnaissance by bottom stream sediment sampling, has delineated an area of high metal content in the north central sector of the North Creek Watershed. Development of a geochemical model, relating to the relative chemical concentrations derived from the chemical analyses of bottom sediments, suspended sediments, stream waters and well waters collected from the north central sector, was designed to discover the source of the anomaly. Samples of each type of material were analysed by the A.R.L. Direct Reading Multi-element Emission Spectrograph Q.A. 137 for elements: Na, K, Ca, Sr, Si, As, Pb, Zn, Cd, Ni, Ti, Ag, Mo, Be, Fe, AI, Mn, Cu, Cr, P and Y. Anomalous results led to the discovery of a spring, the waters of which carried high concentrations of Zn, Cd, Pb, As, Ni, Ti, Ag, Sr and Si. In addition, the spring waters had high concentrations of Na, Ca, Mg, 504 , alkalinity, N03' and low concentrations of K, Cl and NH3. Increased specific conductivity (up to 2500 ~mho/cm.) was noted in the spring waters as well as increased calculated total dissolved solids (up to 2047 mg/l) and increased ionic strength (up to 0.06). On the other hand, decreases were noted in water temperature (8°C), pH (pH 7.2) and Eh (+.154 volts). Piezometer nests were installed in the anomalous north central sector of the watershed. In accordance with the slope of the piezometric surface from wells cased down to the till/bedrock interface, groundwater flow is directed from the recharge area (northwest of the anomaly) towards the artesian spring via the highly fractured dolostone aquifer of the Upper Eramosa Member. The bedrock aquifer is confined by the overlying Halton till and the underlying Lower Eramosa Member (Vinemount Shale). The oxidation of sphalerite and galena and the dissolution of gypsum, celestite, calcite, and dolomite within the Eramosa Member, contributed its highly, dissolved constituents to the circulating groundwaters, the age of which is greater than 20 years as determined by tritium dating. Groundwater is assumed to flow along the Vinemount Shale and discharge as an artesian spring where the shale unit becomes discontinuous. The anomaly is located on a topographic low where bedrock is close to the surface. Thermodynamic evaluation of the major ion speciation from the anomalous spring and surface waters, showed gypsum to be supersaturated in these spring waters. Downstream from the spring, the loss of carbon dioxide from the spring waters resulted in the supersaturation with respect to calcite, aragonite, magnesite and dolomite. This corresponded with increases in Eh (+.304 volts) and pH (pH 8.5) in the anomalous surface waters. In conclusion, the interaction of groundwaters within the highly, mineralized carbonate source (Eramosa Member) resulted in the characteristic Ca*Mg*HC03*S04 spring water at the anomalous site, which appeared to be the principle effect upon controlling the anomalous surface water chemistry.

Environmental assessment and biomonitoring of the Twelve Mile Creek watershed, Niagara Peninsula, Ontario

In light of the heavy reliance of the people of the Niagara Peninsula on the T\\'elve Mile Creek (TMC) watershed for recreational activities and for municipal and industrial uses ( e.g., drinking water, shipping and discharge of effluents), it was deemed prudent to assess the envirol1tnental health of the system by analysing the sediments total and exchangeable metal, and TPH contents. The MOEE has set guidelines with limits for the protection and management of aquatic sediments, and the sediments from the headwaters of the TMC have total metal and TPH (subset of O&G) contents well below the lower provincial limits. Areas of environmental concern where total metal contents in sediments, either individually or collectively, exceed the guideline, are the south side of Lake Gibson, the Old WeIland Canal, a segment of TMC just south of the QEW and Martindale Pond. The total metal content of sediments does not in all instances identify areas of biological concern. Instead, it has been found that the exchangeable metal fraction of sediments is a better indicator of metal availability and thus potential accumulation in organisms. In some instances, the exchangeable metal fraction agrees with the total metal fraction defining areas of environmental concern, but it does vary from site to site reflecting the natural variability of the ambient environment. Overall, the exchangeable metal fraction of sediments appears to be a better indicator of anthropogenic pollution and ecosystem impact. A histochemical study of Anodon.ta sp., Elliptio sp. and zebra mussels (Dreissena polyn'101pha) was done in conjunction with passive biomonitoring of zebra and quagga mussels (Dreissena bugensis) from the Twelve Mile Creek watershed and Lake 51. Clair (Jeanette's Creek, Chatham, Ontario). The highest concentrations of divalent metals such as Cu, Ni, Cd, and Zn, and trivalent Al appear to accumulate in gill and kidney tissues. Metal contents of organ tissues in Anodonta sp. vary with size class. Organ metal content varies among size classes, thus requiring consideration of size in biomonitoring studies. Shucked zebra and quagga mussel tissues, exhibited similar size class to Al content trends. In addition they reflected the Al content trends of top (approximately 10 cm) most sediments in the Twelve Mile Creek watershed. Quagga mussels appear to have higher Al concentrations than zebra mussels, thus suggesting that quagga mussels may be better passive biomonitors of AI. Cd content in zebra mussel tissues, seemed to increase with size class trends. This was not demonstrated in the quagga mussel tissues. This suggests that Cd may be regulated by quagga mussels and not by zebra mussels, and that zebra mussels may be better passivebiomonitors of Cd than are quagga mussels. Zebra mussel, quagga mussel, Anodonta sp., and Elliptio sp. were used in a two part, active (translocated) biomonitoring study of the Twelve Mile Creek watershed. There was no statistical difference in death rates between zebra and quagga mussels after 65 days of biomonitoring. However there does appear to be a difference of death rates between sites. Unfortunately the data base did not permit us to differentiate between sites. Relative to Port Colborne Harbour (Port Colborne, Ontario), the Twelve Mile Creek watershed appears to be elevated in bioavailable AI. An area near the terminus of the Twelve Mile Creek appears to be an area of environmental concern since mussels seemed to have accumulated relatively large concentrations of Cd, Zn, and Pb. In addition to possible metal loading from a nearby outfalls, or possible upstream outfalls, road salt runoff from storm sewers may have contributed to metal accumulation through cation exchanges processes. Similar trends in cumulative quagga mussel metal concentrations during the two time periods (65 and 159 days), suggest that quagga mussels may reach equilibrium within 65 days of translocation. Differences in bioaccumulated metal concentrations of the two dreissenid species demonstrate that active biomonitoring studies must use a variety of organisms to adequately assess the environmental situation of specific waterways and/or bodies.

THE ACUTE EFFECTS OF A SINGLE SESSION OF PLYOMETRIC EXERCISE ON MARKERS OF BONE TURNOVER IN BOYS AND MEN

The study objective was to compare the response of bone markers to an exercise session consisting of high mechanical loading (144 jumps) between boys (n=12, 10.2 ± 0.4 years) and men (n=18, 22.5 ± 0.7 years). Blood samples were collected at pre-, 5, 60 minutes post-, and 24 hours post-exercise) to measure bone-specific alkaline phosphatase (BAP), amino-terminal cross-linking telopeptide (NTx), osteoprotegrin (OPG) and receptor activator of nuclear factor kb ligand (RANKL). Boys had higher BAP levels at all time points, with an increase 24 hours post-exercise. No such increase was observed in men. Likewise, NTx levels were higher in boys, with a greater increase over time than in men. OPG and RANKL levels were similar in boys and men at all times. In summary, even one session of exercise stimulates bone turnover, as reflected in the increase in both BAP and NTx, in boys (but not men) within 24 hours.

Sample preparation and heavy metal determination by atomic spectrometry /

Microwave digestions of mercury in Standards Reference Material (SRM) coal samples with nitric acid and hydrogen peroxide in quartz vessels were compared with Teflon® vessel digestion by using flow injection cold vapor atomic absorption spectrometry. Teflon® vessels gave poor reproducibiUty and tended to deliver high values, while the digestion results from quartz vessel show good agreement with certificate values and better standard deviations. Trace level elements (Ag, Ba, Cd, Cr, Co, Cu, Fe, Mg, Mn, Mo, Pb, Sn, Ti, V and Zn) in used oil and residual oil samples were determined by inductively coupled plasma-optical emission spectrometry. Different microwave digestion programs were developed for each sample and most of the results are in good agreement with certified values. The disagreement with values for Ag was due to the precipitation of Ag in sample; while Sn, V and Zn values had good recoveries from the spike test, which suggests that these certified values might need to be reconsidered. Gold, silver, copper, cadmium, cobalt, nickel and zinc were determined by continuous hydride generation inductively coupled plasma-optical emission spectrometry. The performance of two sample introduction systems: MSIS™ and gas-liquid separator were compared. Under the respective optimum conditions, MSIS^"^ showed better sensitivity and lower detection limits for Ag, Cd, Cu, Co and similar values for Au, Ni and Zn to those for the gas-liquid separator.

Composition analysis of high-Tc superconducting thin films by quantitative x-ray fluorescence

A method is presented for determining the composition of thin films containing the elements Bi, Sr, Br, Cu, and Ca. Quantitative x-ray fluorescence (XRF) consisting of radioactive sources (secondary foil excitor 241Am-Mo source and 55Pe source), a Si(Li) detector, and a multichannel analyzer were employed. The XRF system was calibrated by using sol gel thin films of known element composition and also by sputtered thin films analyzed by the conventional Rutherford Back Scattering (RBS). The XRF system has been used to assist and optimize the sputter target composition required to produce high-Tc BiSrCaCuO films with the desired metal composition.

Single-Molecule Magnets and Multifunctional Molecular Magnetic Materials Based on Polynuclear Metal Complexes

Our work on single molecule magnets and multifunctional magnetic materials is presented in four projects. In the first project we show for first time that heteroatomic-type pseudohalides, such as OCN-, can be employed as structure-directing ligands and ferromagnetic couplers in higher oxidation state metal cluster chemistry. The initial use of cyanato groups in Mn cluster chemistry has afforded structurally interesting MnII/III14 (1) and MnII/III/IV16 (2) clusters in which the end-on bridging cyanates show a preference in binding through their O-atom. The Mn14 compound shows entirely visible out-of-phase alternating currect signals below 5 K and large hysteresis loops below 2 K. Furthermore, the amalgamation of azido groups with the triethanolamine tripodal ligand in manganese carboxylate cluster chemistry has led to the isolation of a new ferromagnetic, high-nuclearity and mixed-valence MnII/III15Na2 (3) cluster with a large ground-state spin value of S = 14. In the second project we demonstrate a new synthetic route to purely inorganic-bridged, transition metal-azido clusters [CoII7 (4) and NiII7 (5)] and coordination polymers [{FeII/III2}n (6)] which exhibit strong ferromagnetic, SMM and long-range magnetic ordering behaviors. We also show that access to such a unique ferromagnetic class of inorganic, N-rich and O-free materials is feasible through the use of Me3SiN3 as the azido-ligand precursor without requiring the addition of any organic chelating/bridging ligand. In the last projects we have tried to bring together molecular magnetism and optics via the synthesis of multifunctional magnetic materials based on 3d- or 4f-metal ions. We decided to approach such challenge from two different directions: firstly, in our third project, by the deliberate replacement of non-emissive carboxylato ligands in known 3d-SMMs with their fluorescent analogues, without perturbing the metal-core structure and SMM properties (complexes 7, 8, and 9). The second route (last project) involves the use of naphthalene or pyridine-based polyalcohol bridging ligands for the synthesis of new polynuclear LnIII metal clusters (Ln = lanthanide) with novel topologies, SMM behaviors and luminescent properties arising from the increased efficiency of the “antenna” organic group. This approach has led us to the isolation of two new families of LnIII8 (complexes 10-13) and LnIII4 (complexes 14-20) clusters.

High-Spin and Emissive Molecular Materials: Synthesis and Characterization of New Polynuclear Ni(II) Complexes from the Use of Aromatic Schiff Bases as Bridging Ligands

The employment of the bridging/chelating Schiff bases, N-salicylidene-4-methyl-o-aminophenol (samphH2) and N-naphthalidene-2-amino-5-chlorobenzoic acid (nacbH2), in nickel cluster chemistry has afforded eight polynuclear Ni(II) complexes with new structural motifs, interesting magnetic and optical properties, and unexpected organic ligand transformations. In the present thesis, Chapter 1 deals with all the fundamental aspects of polynuclear metal complexes, molecular magnetism and optics, while research results are reported in Chapters 2 and 3. In the first project (Chapter 2), I investigated the coordination chemistry of the organic chelating/bridging ligand, N-salicylidene-4-methyl-o-aminophenol (samphH2). The general NiII/tBuCO2-/samphH2 reaction system afforded two new tetranuclear NiII clusters, namely [Ni4(samph)4(EtOH)4] (1) and [Ni4(samph)4(DMF)2] (2), with different structural motifs. Complex 1 possessed a cubane core while in complex 2 the four NiII ions were located at the four vertices of a defective dicubane. The nature of the organic solvent was found to be of pivotal importance, leading to compounds with the same nuclearity, but different structural topologies and magnetic properties. The second project, the results of which are summarized in Chapter 3, included the systematic study of a new optically-active Schiff base ligand, N-naphthalidene-2-amino-5-chlorobenzoic acid (nacbH2), in NiII cluster chemistry. Various reactions between NiX2 (X- = inorganic anions) and nacbH2 were performed under basic conditions to yield six new polynuclear NiII complexes, namely (NHEt3)[Ni12(nacb)12(H2O)4](ClO4) (3), (NHEt3)2[Ni5(nacb)4(L)(LH)2(MeOH)] (4), [Ni5(OH)2(nacb)4(DMF)4] (5), [Ni5(OMe)Cl(nacb)4(MeOH)3(MeCN)] (6), (NHEt3)2[Ni6(OH)2(nacb)6(H2O)4] (7), and [Ni6(nacb)6(H2O)3(MeOH)6] (8). The nature of the solvent, the inorganic anion, X-, and the organic base were all found to be of critical importance, leading to products with different structural topologies and nuclearities (i.e., {Ni5}, {Ni6} and {Ni12}). Magnetic studies on all synthesized complexes revealed an overall ferromagnetic behavior for complexes 4 and 8, with the remaining complexes being dominated by antiferromagnetic exchange interactions. In order to assess the optical efficiency of the organic ligand when bound to the metal centers, photoluminescence studies were performed on all synthesized compounds. Complexes 4 and 5 show strong emission in the visible region of the electromagnetic spectrum. Finally, the ligand nacbH2 allowed for some unexpected organic transformations to occur; for instance, the pentanuclear compound 5 comprises both nacb2- groups and a new organic chelate, namely the anion of 5-chloro-2-[(3-hydroxy-4-oxo-1,4-dihydronaphthalen-1-yl)amino]benzoic acid. In the last section of this thesis, an attempt to compare the NiII cluster chemistry of the N-naphthalidene-2-amino-5-chlorobenzoic acid ligand with that of the structurally similar but less bulky, N-salicylidene-2-amino-5-chlorobenzoic acid (sacbH2), was made.