Novel environmental pollution control catalysts.

This thesis comprises of the analysis of a commercial three way catalyst (TWC), as well as the discovery, development and analysis of a novel environmental pollution control catalyst for the abatement of automobile exhaust gases (namely CO by oxidation, HC (propane) by oxidation and NOX by reduction. All work was undertaken in collaboration with Blackthorn Autocatalysts, Chichester, West Sussex. The commercial TWC work comprised of two parts: (i) catalytic poisoning effects on the commercial TWC by metal compounds used in lead replacement petrol on activity of CO oxidation and HC oxidation. (ii) platinum group metal losses from the commercial TWC during laboratory simulation of an automobile exhaust gas during normal driving conditions. Here the author finds that (i) is more significant than (ii). The work on the novel catalyst also comprises of two parts: (i) The activity of a Keggin-type catalyst of the form [AlO4Al12(OH)24(H2O)12]7+ was compared to that of the TWC with respect to CO oxidation, HC oxidation and NOX reduction with varying Fe3+/Al3+ and Au3+/Fe3+/Al3+ substitutions. Comparisons of various preparative methods are made. Selected catalysts are characterised and probed in depth. (ii) A spinel-type catalyst of the form %Au/CoXFe3-XO4 was selected and activity with respect to CO oxidation, HC oxidation and NOX reduction with varying values of x and Au3+ loadings were compared to the TWC. It was characterised in full. Fe substituted Keggins-type catalysts proved to compare favourably with a commercial TWC in HC oxidation, but no CO oxidation and proved to be thermally unstable at the high temperatures experienced by TWCs. 1% Au containing cobalt-ferrite spinel-type catalysts of the form COXFe3-XO4 were x = 1.5 proved to compare very favourable when compared to the commercial TWC. Achieving lower LOTs for CO and HC oxidation under stoichiometric conditions. It was also found to be very active in NOX reduction under net reducing conditions. These Au/CoXFe3-XO4 catalysts were readily supported on pre-calcined Fecralloy at a level of 0.2 wt%, but more work is required to achieve higher loadings and higher activities. The application of such materials to the catalysis of environmental pollution control could be significant

Job Satisfaction in Agile Development Teams: Agile Development as Work Redesign

Agile software-development advocates claim that an important value proposition of agile methods is that they make people more motivated and satisfied with their jobs. While several studies present anecdotal evidence that agile methods increase motivation and satisfaction, research has not theoretically explained or empirically examined how agile development practices relate to team members’ feelings about their work. Drawing on the management and software-development literature, we articulate a model of job design that connects agile development practices to perceptions of job characteristics and, thereby, improve agile team members’ job satisfaction. Using data collected from 252 software-development professionals, we tested the model and found a positive relationship between agile project-management and software-development practices and employees’ perceptions of job characteristics. Further, we found direct effects between agile development-practice use and job satisfaction. Finally, we found interaction effects between the use of agile project-management and software-development approaches and the perception of job autonomy. With this study, we contribute to the literature by theoretically explaining and directly evaluating agile development practices’ impact on individuals’ perceptions about their job characteristics and on their job satisfaction

A Second-Generation Device for Automated Training and Quantitative Behavior Analyses of Molecularly-Tractable Model Organisms

A deep understanding of cognitive processes requires functional, quantitative analyses of the steps leading from genetics and the development of nervous system structure to behavior. Molecularly-tractable model systems such as Xenopus laevis and planaria offer an unprecedented opportunity to dissect the mechanisms determining the complex structure of the brain and CNS. A standardized platform that facilitated quantitative analysis of behavior would make a significant impact on evolutionary ethology, neuropharmacology, and cognitive science. While some animal tracking systems exist, the available systems do not allow automated training (feedback to individual subjects in real time, which is necessary for operant conditioning assays). The lack of standardization in the field, and the numerous technical challenges that face the development of a versatile system with the necessary capabilities, comprise a significant barrier keeping molecular developmental biology labs from integrating behavior analysis endpoints into their pharmacological and genetic perturbations. Here we report the development of a second-generation system that is a highly flexible, powerful machine vision and environmental control platform. In order to enable multidisciplinary studies aimed at understanding the roles of genes in brain function and behavior, and aid other laboratories that do not have the facilities to undergo complex engineering development, we describe the device and the problems that it overcomes. We also present sample data using frog tadpoles and flatworms to illustrate its use. Having solved significant engineering challenges in its construction, the resulting design is a relatively inexpensive instrument of wide relevance for several fields, and will accelerate interdisciplinary discovery in pharmacology, neurobiology, regenerative medicine, and cognitive science

Novel environmental pollution control catalysts

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BYPASS-OMA: Hypoglycemic Hyperinsulinemic Nesidioblastosis after Gastric Bypass Surgery—A Case Report and Review of the Literature

This rare case vignette describes hypoglycemic, hyperinsulinemic nesidioblastosis in a female patient with prior Roux-en-Y gastric bypass. The patient presented with severe symptomatic hypoglycemia resistant to IV dextrose and diazoxide, requiring surgical resection. Traditional imaging found nonspecific findings, and biochemical analysis was inconsistent with insulinoma. A gallium-68 dotatate PET scan was utilized to successfully localize the tumor in the distal pancreas. She underwent laparoscopic resection of the distal pancreatic lesion with resolution of her symptoms and return to euglycemia. The histological evaluation confirmed the diagnosis of nesidioblastosis. Nesidioblastosis is a rare complication of bariatric surgery that may be more clinically relevant with rising prevalence of obesity. Diagnosis with conventional imaging modalities may be challenging; however, the dotatate PET scan may have high utility in detecting lesions. It is essential for clinicians to consider nesidioblastosis in the differential diagnosis of hyperinsulinemic hypoglycemic conditions and recognize there may be a link with increasing rates of bariatric surgery

A Data-Based Conservation Planning Tool for Florida Panthers

Habitat loss and fragmentation are the greatest threats to the endangered Florida panther (Puma concolor coryi). We developed a data-based habitat model and userfriendly interface so that land managers can objectively evaluate Florida panther habitat. We used a geographic information system (GIS) and the Mahalanobis distance statistic (D2) to develop a model based on broad-scale landscape characteristics associated with panther home ranges. Variables in our model were Euclidean distance to natural land cover, road density, distance to major roads, human density, amount of natural land cover, amount of semi-natural land cover, amount of permanent or semipermanent flooded area–open water, and a cost–distance variable. We then developed a Florida Panther Habitat Estimator tool, which automates and replicates the GIS processes used to apply the statistical habitat model. The estimator can be used by persons with moderate GIS skills to quantify effects of land-use changes on panther habitat at local and landscape scales. Example applications of the tool are presented