This thesis proposes a modified structure model for graphite oxide (GO), an important precursor in graphene chemistry, develops a new strategy to convert GO back to graphene-like structure, and demonstrates its possible applications in both water purification and supercapacitor technologies. GO, a nontraditional compound first obtained from graphite oxidation over 150 years ago, is now becoming an important player in the production of graphene-based materials, which has high technological relevance. GO structure and reduction have been vigorously investigated, but its precise chemical structure still remains obscure, and the complete restoration of the sp2 carbon lattice has not yet been achieved. In our work, solid state 13C NMR (MAS) analysis offered a piece of evidence for five or six-membered ring lactol structure existing in GO that had never been assigned before, leading to a modified Lerf-Klinowski model for GO. A three-step reduction strategy, involving sodium borohydride (NaBH4), sulfuric acid, and high temperature thermal annealing, described in the thesis, successfully reduced GO back to chemically converted graphene (CCG) with the lowest heteroatom abundance among all those previously reported. In addition to the chemical significance of graphene/CCG production, GO and its derivatives were used as novel adsorbents in water purification. GO-coated sand showed higher retention than ordinary sand for both Rhodamine B and mercuric ion (Hg2+) contaminants in water. Further functionalization of GO with thiophenol resulted in better adsorption capacity toward Hg2+ than that of activated carbon. In addition, free-standing films of GO were treated and reduced with a CO2 laser beam into different conductive reduced GO (RGO) patterns, and directly used as supercapacitor devices which showed good cyclic stability and energy storage capacities comparable to that of existing thin film ultracapacitors. GO turned out to be a solid electrolyte with anisotropic proton conductivity similar to Nafion, while the large amount of trapped water in GO played an important role.

In multiple-input multiple-output (MIMO) systems, the use of lattice reduction methods such as the one proposed by Lenstra-Lenstra-Lovasz (LLL) significantly improves the performance of the suboptimal solutions like zero-forcing (ZF) and zero-forcing deceision-feedback-equalizer (ZF-DFE). Today's high rate data communication demands faster lattice reduction methods. Taking advantage of the temporal correlation of a Rayleigh fading channel, a new method is proposed to reduce the complexity of the lattice reduction methods. The proposed method achieves the same error performance as the original lattice reduction methods, but significantly reduces the complexity of lattice reduction algorithm. The proposed method can be used in any MIMO scenario, such as the MIMO detection, and broadcast cases, which are studied in this work.

Drag reduction in turbulent pipe flow using polymeric and surfactant additives is well known. Although extensive research work has been carried out on the drag reduction behavior of polymers and surfactants in isolation, little progress has been made on the synergistic effects of combined polymers and surfactants. In this work the interactions between drag-reducing polymers and surfactants were studied. The drag-reducing polymers studied were nonionic polyethylene oxide (referred to as PEO) and anionic copolymer of acrylamide and sodium acrylate (referred to as CPAM). The drag-reducing surfactants studied were nonionic ethoxylated alcohol - Alfonic 1412-7 (referred to as EA), cationic surfactant - Octadecyltrimethylammonium chloride in pure powder form (referred to as OTAC-p) and commercial grade cationic surfactant - Octadecyltrimethylammonium chloride in isopropanol solvent - Arquad 18-50 (referred to as OTAC-s). The interactions between polymers and surfactant were reflected in the measurements of the physical properties such as electrical conductivity, surface tension, viscosity and turbidity. The critical micelle concentration (cmc) of the mixed polymer / surfactant system was found to be different from that of the surfactant alone. The viscosity of a polymer solution was significantly affected by the addition of surfactant. Weak interactions were observed for the mixed systems of nonionic polymer - nonionic surfactant and anionic polymer - nonionic surfactant. Due to the wrapping of polymer chains around the developing micelles, a minimum in the viscosity is observed in these two cases. In the case of nonionic polymer / cationic surfactant system, the change in the viscosity was found to depend on the polymer concentration (C) and the critical entanglement concentration (C*). When the polymer concentration (C) was less than C* (C < C*), the plot of the viscosity versus surfactant concentration exhibited a minimum. When C > C*, a maximum in the viscosity versus surfactant concentration plot was observed. The interactions between nonionic polymer and cationic surfactant were observed to increase with the increase in temperature. A large drop in the viscosity occurred in the case of anionic-polymer / cationic-surfactant system when surfactant was added to the polymer solution. The observed changes in the viscosity are explained in terms of the changes in the extension of polymeric chains resulting from polymer-surfactant interactions. The anionic CPAM chains collapsed upon the addition of cationic OTAC-p, due to charge neutralization. The presence of counterion sodium salicylate (NaSal) stabilized the cationic surfactant monomers in the solution, resulting in micelle formation at a surfactant concentration well below the concentration where complete charge neutralization of anionic polymer occurred. Preliminary results are reported on the pipeline drag reduction behavior of mixed polymer-surfactant system. The results obtained using combinations of CPAM / OTAC-p in pipeline flow are found to be in harmony with the interaction study. Due to the shrinkage of CPAM chains upon the addition of OTAC-p, the drag reducing ability of CPAM is compromised.

Individuals tend to underestimate situational causes and overly rely on trait causes in explaining negative behaviors of outgroup members, a tendency named the ultimate attribution error (Pettigrew, 1979). This attributional pattern is directly related to stereotyping, because attributing negative behaviors to internal, stable causes tends to perpetuate negative stereotypes of outgroup members. Recent research on implicit bias reduction revealed that circumventing individuals’ tendency to engage in the ultimate attribution error led to reduced stereotyping. More specifically, training White participants to consider situational factors in determining Blacks’ negative stereotypic behaviors led to decreased automatic stereotype activation. This technique was named Situational Attribution Training (Stewart, Latu, Kawakami, & Myers, 2010). In the current studies, I investigated the mechanisms and moderators of Situational Attribution Training. In Study 1, I investigated the effect of training on spontaneous situational inferences. Findings revealed that training did not increase spontaneous situational inferences: both training and control participants showed evidence of spontaneous situational inferences. In Study 2, I investigated whether correcting trait inferences by taking into account situational factors has become automatic after training. In addition, explicit prejudice, motivations to control prejudice, and cognitive complexity variables (need for cognition, personal need for structure) were investigated as moderators of training success. These findings revealed that Situational Attribution Training works best for individuals high in need for cognition, under conditions of no cognitive load, but not high cognitive load. Training increased implicit bias for individuals high in modern racism, regardless of their cognitive load. Possible explanations of these findings were discussed, including methodological limitations and theoretical implications.

The present research explored the effects of Situational Attribution Training (Stewart, Latu, Kawakami, & Myers, 2010) on affective bias utilizing facial electromyography (EMG). Participants viewed a slideshow of randomly presented photographs of both and White and Black American men while rating how “friendly” each individual appeared. Simultaneously, corrugator and zygomaticus region activity, linked with positive and negative affect, respectively, was measured. Of these participants, half were randomly assigned to complete Situational Attribution Training beforehand. Results for EMG activity suggested no significant differences in EMG activity for White compared to Black photographs for either the training or control participants; thus, this study did not find evidence of affective bias by way of corrugator or zygomaticus activity. However, errors in slideshow presentation prevent clear interpretation of these results. Suggestions for future research and ways in which bias errors can be avoided are discussed.

In multiple-input multiple-output (MIMO) systems, the use of lattice reduction methods such as the one proposed by Lenstra-Lenstra-Lovasz (LLL) significantly improves the performance of the suboptimal solutions like zero-forcing (ZF) and zero-forcing deceision-feedback-equalizer (ZF-DFE). Today's high rate data communication demands faster lattice reduction methods. Taking advantage of the temporal correlation of a Rayleigh fading channel, a new method is proposed to reduce the complexity of the lattice reduction methods. The proposed method achieves the same error performance as the original lattice reduction methods, but significantly reduces the complexity of lattice reduction algorithm. The proposed method can be used in any MIMO scenario, such as the MIMO detection, and broadcast cases, which are studied in this work.

Drag reduction in turbulent pipe flow using polymeric and surfactant additives is well known. Although extensive research work has been carried out on the drag reduction behavior of polymers and surfactants in isolation, little progress has been made on the synergistic effects of combined polymers and surfactants. In this work the interactions between drag-reducing polymers and surfactants were studied. The drag-reducing polymers studied were nonionic polyethylene oxide (referred to as PEO) and anionic copolymer of acrylamide and sodium acrylate (referred to as CPAM). The drag-reducing surfactants studied were nonionic ethoxylated alcohol - Alfonic 1412-7 (referred to as EA), cationic surfactant - Octadecyltrimethylammonium chloride in pure powder form (referred to as OTAC-p) and commercial grade cationic surfactant - Octadecyltrimethylammonium chloride in isopropanol solvent - Arquad 18-50 (referred to as OTAC-s). The interactions between polymers and surfactant were reflected in the measurements of the physical properties such as electrical conductivity, surface tension, viscosity and turbidity. The critical micelle concentration (cmc) of the mixed polymer / surfactant system was found to be different from that of the surfactant alone. The viscosity of a polymer solution was significantly affected by the addition of surfactant. Weak interactions were observed for the mixed systems of nonionic polymer - nonionic surfactant and anionic polymer - nonionic surfactant. Due to the wrapping of polymer chains around the developing micelles, a minimum in the viscosity is observed in these two cases. In the case of nonionic polymer / cationic surfactant system, the change in the viscosity was found to depend on the polymer concentration (C) and the critical entanglement concentration (C*). When the polymer concentration (C) was less than C* (C < C*), the plot of the viscosity versus surfactant concentration exhibited a minimum. When C > C*, a maximum in the viscosity versus surfactant concentration plot was observed. The interactions between nonionic polymer and cationic surfactant were observed to increase with the increase in temperature. A large drop in the viscosity occurred in the case of anionic-polymer / cationic-surfactant system when surfactant was added to the polymer solution. The observed changes in the viscosity are explained in terms of the changes in the extension of polymeric chains resulting from polymer-surfactant interactions. The anionic CPAM chains collapsed upon the addition of cationic OTAC-p, due to charge neutralization. The presence of counterion sodium salicylate (NaSal) stabilized the cationic surfactant monomers in the solution, resulting in micelle formation at a surfactant concentration well below the concentration where complete charge neutralization of anionic polymer occurred. Preliminary results are reported on the pipeline drag reduction behavior of mixed polymer-surfactant system. The results obtained using combinations of CPAM / OTAC-p in pipeline flow are found to be in harmony with the interaction study. Due to the shrinkage of CPAM chains upon the addition of OTAC-p, the drag reducing ability of CPAM is compromised.

Polymer electrolyte membrane fuel cells (PEFCs) have long been thought of as a promising clean alternative energy electrochemical device. They are lightweight, highly efficient, modular and scalable devices. A fuel such as H2 or methanol that can be readily produced from a variety of sources can be utilized in PEFCs to generate electricity with low or no emissions. Despite these advantages, fuel cell technologies have failed to reach mass commercialization mainly due to short operational lifetimes and the high cost of materials. In particular, the polymer membrane and the catalyst layer have been problematic in reducing the material cost. Currently, platinum is the dominant material used to catalyze fuel cell reactions. However platinum is very expensive and scarce. In order to pursue the mass commercialization of fuel cells, two methods have been proposed: 1) increasing the utilization of platinum to lower the loading required, and 2) replacing platinum completely with a non-precious material. The latter has been suggested to be the long term solution due to the increasing cost of platinum. This thesis explores the elimination of platinum through the use of nanostructured non-precious metal catalysts for polymer electrolyte fuel cells. Several catalysts have been synthesized without the use of platinum that are active for the oxygen reduction reaction (ORR) which occurs at the cathode. Three different synthetic techniques were utilized using different nitrogen precursors. Aside from the different nitrogen precursors, each set of experiments utilize a different approach to optimize the oxygen reduction performance. Different characterization techniques are used to learn more about the ORR on non-precious metal fuel cells. The first experiment utilizes ethylenediamine, a well-known nitrogen precursor for non-precious metal fuel cell catalysts. Ethylenediamine is deposited onto two different porous carbon black substrates to determine the effectiveness of different porosities in creating active sites for the ORR. Of the two carbon black species, Ketjenblack EC-600JD and Ketjenblack ED-300J, the former was found to be more porous and effective. This result was mainly attributed to the increased surface area of the carbon black which allowed for better dispersion and a greater active site density. In this experiment, the coating of ethylenediamine on carbon black was also refluxed for 3 hours prior to the pyrolysis. It was found that refluxed catalyst samples showed much improved performance than catalyst samples without this procedural modification. The next experiment utilized cyanamide as a nitrogen precursor. Cyanamide was chosen due to its ability to form larger amounts of pyridinic nitrogen on the surface of the catalyst after a high temperature pyrolysis stage. The catalysts were heat-treated at 1000oC and the performance was measured. NH3 was introduced during the pyrolysis, which could remove the excess coating from the carbon surface, and increase the surface area of the catalyst by unblocking the carbon pores. A third modification to the procedure was carried out, where the heat-treated sample was ball-milled, re-coated, and heat-treated again in ammonia conditions to increase the nitrogen functionalities and increase the active site density. The performance was slightly increased from the original heat-treated sample. However due to the decreased surface area, the limiting current density also decreased. It was believed that ball-milling the sample crushed the pores within the catalyst sample, thereby lowering the active surface area and thus the current density. Therefore, the last sample was prepared similarly to the procedure for the third sample, but without ball-milling. This sample had restored surface area and improved ORR performance over all the synthesized catalyst samples – these experiments allowed for important realizations regarding the nature of the Fe-cyanamide-KJ600 catalysts and allowed for a drastic improvement in onset and half-wave potentials from the first catalyst. The final experiment discussed in this thesis describes the work done with 1,2,4,5-tetracyanobenzene and tetracyanoethylene as phthalcyanine precursors for non-precious metal catalysts (NPMCs). Iron(II) acetate was mixed with these phthalocyanine precursors to form polymer sheets of iron phthalocyanine or its monomeric units. By the creation of these polymer sheets of iron phthalocyanine, it allowed for a uniform distribution of iron centres on the surface of the carbon after a heat-treatment step. This allowed for high active site density through the design of these sheet polymers and prevented agglomeration or blockage of active sites which is thought to be a common problem in the synthesis of many NPMCs. Both tetracyanobenzene and tetracyanoethylene as precursors were tested. The tetracyanobenzene catalyst was heat-treated at different temperature ranging from 700-1100oC and characterized through electrochemical tests for the ORR. As an overall conclusion to this work, several catalyst samples were made and different approaches were successfully employed to improve the ORR performance. Of the synthesis treatments utilized to improve performance, each specific catalyst had different parameters to tweak in order to improve ORR performance. With X-ray photoelectron spectroscopy (XPS) analysis, conclusions were also specific to the catalysts structure and synthesis procedure, however quaternary and pyrrolic nitrogen groups seemed to play an influential role to the ORR final performance. Although relative amount of pyridinic nitrogen was not seen to increase with increasing catalyst performance during the studies; it may still play an essential role in the reduction of oxygen on the catalyst surface. The author of this work has not ruled out that possibility. Several recommendations for future work were suggested to broaden the knowledge and understanding of nanostructure non-precious metal catalysts to design a high performing, durable, and low-cost alternative to platinum based catalysts.

The extensive amount of platinum required in order to facilitate the oxygen reduction reaction (ORR) occuring at the cathode of low temperature fuel cells provides cost limitations to the sustainable commercialization of this technology. The development of electrocatalyst materials with either reduced or eliminated platinum dependency is an urgent necessity. The present work investigates the application of nitrogen doped carbon nanotubes (N-CNTs) and their composites as electrocatalyst materials for the ORR. First, N-CNTs are investigated as platinum support materials for proton exchange membrane fuel cells. They were found to result in improved ORR activity in comparison with undoped CNT supported platinum, due to the enhanced catalyst-support interactions and electronic properties induced by nitrogen heteroatoms incorporated into the graphitic structure of CNTs. Second, N-CNTs synthesized from a variety of different precursor materials were investigated as ORR electrocatalysts in alkaline conditions. The influence of the precursor materials was illustrated with improved ORR activity and nitrogen concentration observed for N-CNTs synthesized with precursor materials containing higher nitrogen to carbon contents. Highly active N-CNTs based on ethylenediamine were fabricated into thin, free standing films for use as a stand-alone cathode catalyst layer in an alkaline anion exchange membrane fuel cell. Finally, metal-free N-CNTs were developed and demonstrated to provide promising ORR in the absence of any metal interactions.

This investigation applied the techniques of polarography and controlled potential electrolytic reduction to the study of a series of unsymmetrical benzils. Eleven unsymmetrical benzils were synthesized and studied in 50% ethanol-water (by volume) solvent systems buffered at pH 1, 5, and 13. The results showed that, with unsymmetrical benzils substituted with electron-withdrawing or electrondonating groups, the carbonyl closest to the ring with the least electron-donating power was the preferred reaction site. However, the dicarbonyl system was nevertheless reduced as a unit, and Hammett sigma values of disubstituted symmetrical benzils were approximately additive. This was ascertained by comparing the ease of reduction of eight unsymmetrical benzils to the ease of reduction of the corresponding disubstituted symmetrical benzils. It was proposed that the electrons were added to the oxygen of one carbonyl, and that the second carbonyl was involved in the reduction chiefly through complete polarization of the dicarbonyl system at the electrode. In general, the reduction of unsymmetrical benzils appeared to follow the same path previously reported for symmetrical benzils.