The mixed metal oxalates, FeCu(ox)₂.3H₂0, CoCu(ox)₂.3H₂0, and NiCu(ox)₂.3.5H₂0, [ox = C₂0₄] have been prepared by coprecipitation from solution. The thermal behaviour of these compounds in nitrogen and in oxygen has been examined using thermogravimetry (TG), thermomagnetometry (TM), differential scanning calorimetry (DSC) and evolved gas analysis (EGA), and results are compared with results obtained for Cuox and Mox.yH₂0. The thermal behaviour of the mixed oxalates, MCU(OX)₂.xH₂0, differed from that of the individual metal oxalates, Cuox, Coox.2H₂0, Niox.2H₂0 and Feox.2H₂0. All three mixed oxalates on heating in N₂, first dehydrate and then decompose in at least two overlapping endothermic stages. Both CO and CO₂ were evolved in proportions which varied with the surrounding atmosphere, and from compound to compound, and with extent of reaction of a given compound. The mixed oxalates, MCU(OX)₂.xH₂0, do not show the exothermic behaviour characteristic of Cuox, and reasons for this are discussed. Thermochemical calculations were done and the enthalpies of formation of the hydrates and dehydrated oxalates were determined. It was found that the enthalpy of mixing was very small or within experimental error. X-ray powder diffraction patterns for the individual and mixed oxalates were compared. The pattern for Cuox differs from the patterns obtained for the other oxalates, confirming suggestions that Cuox has a structure different to most other transition metal oxalates. The kinetics of dehydration and decomposition of the mixed oxalates were investigated, using isothermal and programmed temperature TG and DSC experiments. The yield and composition of evolved gases during isothermal decomposition were measured and compared with the enthalpy changes. X-ray photoelectron spectroscopy studies provided some information on the electron environment of the metal atoms in the various oxalates.

The present study examined the decomposition of neonate pig samples (n = 42) in a freshwater pond located in Holliston, Massachusetts. They were individually placed either in a mesh bag (control group), a trash bag, or a backpack to determine whether trash bags or backpacks affected the rate of decomposition in a freshwater pond. Six pigs were present at each recovery period: two as control specimens, two placed in trash bags, and two placed in backpacks. The neonate pigs were assessed at seven different recovery periods: one week, two weeks, four weeks, twelve weeks, twenty-four weeks, thirty-five weeks, and forty-eight weeks. Throughout the study, decomposition was assessed using the scoring methods of Heaton et al. (2010) and Keough et al. (2017) along with photographs and written descriptions. It was hypothesized that the enclosed remains would decompose at a slower rate than the exposed remains; however, this was not the case. Due to scavenging, the trash bag specimens were removed from statistical analysis. Statistical analyses determined that there was not a statistically significant difference in the Total Body Scores (p = 0.511), the Total Aquatic Decomposition Scores (p = 0.635), and percent mass loss (p = 0.265) between the control groups and the backpack groups.

<p> Our work demonstrates the decomposition results obtained using Ti02 coated paper at different pH, ionic strength, UV intensities, temperature and flow rates. A kinetic model ofTi02 photocatalytic decomposition of reactive azo dye (RBS) was developed for the different conditions. </p> <p> Ti02 coated paper was developed by simply spraying Ti02 suspension on the filter paper. The stability of the Ti02 coated paper was studied and the environment where Ti02 coated paper can be used is under pH 7. The stability of Ti02 attached on the paper surface is determined by the property of the polymeric retention aids and the adsorption of reactive azo dye (RB5) is dependent on the electrostatic attraction. </p> <p> Ti02 photocatalytic decomposition mainly occurs at the surface of Ti02. So the adsorption of RBS molecules is considered to be one of the most important factors, which can affect the decomposition rate. Other factors, such as UV intensity and temperature, can also change the decomposition rate by affecting the formation of free radicals. </p> <p> New discovery of intermediate products can make the mechanism of the photocatalytic decomposition more clear, although the specific information about the intermediate products is not available yet. The adsorption and decomposition of intermediate products provide useful information for developing the decomposition kinetic model. </p> <p> Langmuir adsorption model is fit for the adsorption of RB5 and its degradation intermediate products at Ti02 surface. Our kinetics model combines the principles of Langmuir-Hinshelwood model and two-step first order model. It can describe the change of the RB5 concentration in the bulk and predict the desorption of intermediate products. </p> / Thesis / Master of Applied Science (MASc)

Aluminum is a non-essential trace element that accumulates in human bone tissue (Nayak, 2002). Its toxic effects are cumulative and result in painful forms of renal osteodystrophy, most notably a dynamic bone disease and osteomalacia, but also other forms of disease (Yokel, 2001; Cannata-Andia, 2002). Presently, histological tests of bone biopsies are the only approach for the diagnosis of aluminum-related pathologies (Malluche, 2002). Neutron Activation Analysis was proposed as an alternative method for quantifying aluminum. The Trace Element Group at McMaster University has developed an in vivo procedure for detecting aluminum levels in the bones of the hand, exploiting an accelerator-based approach. A minimum detectable limit (MDL) of 1.14mg of aluminum could be distinguished for a local dose to the hand of 48mSv (Pejovic-Milic, 2001). For the procedure to be clinically effective, the MDL should be comparable to the levels normally contained in healthy subjects (0.3-0.4 mg AI). Further refining of the method is therefore necessary. This dissertation presents an improved algorithm for data analysis, based on Spectral Decomposition. Following phantom measurements, a new MDL of(0.7±0.1)mg AI was reached for a local dose of (20±1)mSv, representing an improvement by a factor of 1.60±0.04. In addition, a time-dependent variant of this algorithm was proposed. The study also addresses the feasibility of a new data acquisition technique, the electronic rejection of the coincident events detected by the Nai(Tl) system. It is expected that the application of this technique, together with Spectral Decomposition Analysis, would provide an acceptable MDL for the method to be valuable in a clinical setting. / Thesis / Master of Science (MS)

Electronic textiles are a sound platform for wearable computing. Many applications have been devised that use sensors placed on these textiles for fields such as medical monitoring and military use or for display purposes. Most of these applications require that the sensors have known locations for accurate results. Activity recognition is one application that is highly dependent on knowledge of the sensor position. Therefore, this thesis presents the design and implementation of a method whereby the location of the sensors on the electronic textile garments can be automatically identified when the user is performing an appropriate activity. The software design incorporates principle component analysis using singular value decomposition to identify the location of the sensors. This thesis presents a method to overcome the problem of bilateral symmetry through sensor connector design and sensor orientation detection. The scalability of the solution is maintained through the use of culling techniques. This thesis presents a flexible solution that allows for the fine-tuning of the accuracy of the results versus the number of valid queries, depending on the constraints of the application. The resulting algorithm is successfully tested on both motion capture and sensor data from an electronic textile garment. / Master of Science

Appalachian mixed hardwood stands along south facing slopes of the Ridge and Valley physiographic province were used to determine fine scale soil respiration (Rs ) and nutrient dynamics among four distinct cover types, white oak (WO, Quercus alba L.), scarlet oak (SO, Quercus coccinea Muech.), chestnut oak (CO, Quercus montana Wild.) and a pine-oak co-dominant cover (PO, Pinus spp. and Quercus spp. (primarily Pinus pungens Lamb. and Q. montana)). Null hypotheses were that: (1) Rs and its relationship to environmental drivers would not differ among the cover types, (2) water and nutrient use efficiencies (WUE and NUE) would not differ among the cover types, and (3) litter decomposition would not differ among the diverse cover types. In 0.02 ha plots, replicated four times, Rs and associated variables (e.g., soil temperature and moisture) were measured. Measurements occurred in three sub-sample locations per plot, from July 2014 - December 2015. In each plot, foliage from two trees of the dominant species were collected to determine WUE using δ¹³C isotope discrimination. Nutrient (N, P and K) content of this fresh foliage was compared with that of litterfall to determine NUE. Litterbags, collected over a one and half year period were used to determine decomposition rate constants for each dominant species. Soil temperature and moisture explained 71% of the variability in Rs. Although only slight, there were statistically significant differences in the Rs models due to cover type. At the same soil temperature, the PO cover type had the highest Rs while the SO, WO cover types had the lowest Rs. WUE, and NUE varied among cover types. SO had significantly greater WUE than the other species, including Table mountain pine, which had the highest NUE. Higher elevation cover types (i.e., PO and CO) ad greater decomposition rate constants. Among the factors driving decomposition, soil C: N ratio had the strongest correlation to decomposition. Correlations between decomposition and productivity variables of total above ground biomass, total stand biomass, and aboveground net primary production also exist. In conclusion, carbon and nutrient cycling varies across the level of cover type within the southern Appalachian hardwood forests. Future efforts to focus on carbon and nutrient dynamics in the context of land use or global change should consider these finer-scale differences. / Ph. D.

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The application of a decomposition methodology to the synthesis/design optimization of a stationary cogeneration fuel cell sub-system for residential/commercial applications is the focus of this work. To accomplish this, a number of different configurations for the fuel cell sub-system are presented and discussed. The most promising candidate configuration, which combines features of different configurations found in the literature, is chosen for detailed thermodynamic, geometric, and economic modeling both at design and off-design. The case is then made for the usefulness and need of decomposition in large-scale optimization. The types of decomposition strategies considered are time and physical decomposition. Specific solution approaches to the latter, namely Local-Global Optimization (LGO) and Iterative Local-Global Optimization (ILGO) are outlined in the thesis. Time decomposition and physical decomposition using the LGO approach are applied to the fuel cell sub-system. These techniques prove to be useful tools for simplifying the overall synthesis/design optimization problem of the fuel cell sub-system. Finally, the results of the decomposed synthesis/design optimization of the fuel cell subsystem indicate that this sub-system is more economical for a relatively large cluster of residences (i.e. 50). To achieve a unit cost of power production of less than 10 cents/kWh on an exergy basis requires the manufacture of more than 1500 fuel cell sub-system units per year. In addition, based on the off-design optimization results, the fuel cell subsystem is unable by itself to satisfy the winter heat demands. Thus, the case is made for integrating the fuel cell sub-system with another sub-system, namely, a heat pump. / Master of Science

No description available.

Strategic network design has significant impacts on the operational performance of transportation and telecommunications industries. The corresponding networks are typically characterized by a multicommodity ow structure where a commodity is defined by a unique origin-destination pair and an associated amount of ow. In turn, multicommodity network design and hub location models are commonly employed when designing strategic networks in transportation and telecommunications applications. In this dissertation, these two modeling approaches are integrated and generalized to address important requirements in network design for truckload transportation and long-distance telecommunications networks. To this end, we first introduce a cost effective relay network design model and then extend this base model to address the specific characteristics of these applications. The base model determines relay point (RP) locations where the commodities are relayed from their origins to destinations. In doing this, we explicitly consider distance constraints for the RP-RP and nonRPRP linkages. In truckload transportation, a relay network (RP-network) can be utilized to decrease drivers' driving distances and keep them within their domiciles. This can potentially help alleviate the high driver turnover problem. In this case, the percentage circuitry, load-imbalance, and link-imbalance constraints are incorporated into the base model to control related performance metrics that are affected by the distance constraints. When compared to the networks from other modeling approaches, the RP-network is more effective in controlling drivers' tour lengths and capable of controlling the empty mileage to low levels without adding a large amount of additional travel distance. In telecommunications, an RP-network can be beneficial in long-distance data transfers where the signals' delity must be improved/regenerated at RPs along their travel paths. For this setting, we extend the base model to include fixed link setup costs and capacities. From our computational results, our models provide better network configuration that is cost effective and facilitates a better service quality (shorter delays and better connectivity). Concerning methodology, we develop effcient exact solution algorithms based on Benders decomposition, Lagrangean decomposition, and Lagrangean relaxation. The performance of the typical solution frameworks are enhanced via numerous accelerating techniques to allow the solution of large-sized instances in reduced solution times. The accelerating techniques and solution approaches are transferable to other network design problem settings with similar characteristics.