abstract: Characterization of petroleum spill site source zones directly influences the selection of corrective action plans and frequently affects the success of remediation efforts. For example, simply knowing whether or not nonaqueous phase liquid (NAPL) is present, or if there is chemical storage in less hydraulically accessible regions, will influence corrective action planning. The overarching objective of this study was to assess if macroscopic source zone features can be inferred from dissolved concentration vs. time data. Laboratory-scale physical model studies were conducted for idealized sources; defined as Type-1) NAPL-impacted high permeability zones, Type-2) NAPL-impacted lower permeability zones, and Type-3) dissolved chemical matrix storage in lower permeability zones. Aquifer source release studies were conducted using two-dimensional stainless steel flow-through tanks outfitted with sampling ports for the monitoring of effluent concentrations and flow rates. An idealized NAPL mixture of key gasoline components was used to create the NAPL source zones, and dissolved sources were created using aqueous solutions having concentrations similar to water in equilibrium with the NAPL sources. The average linear velocity was controlled by pumping to be about 2 ft/d, and dissolved effluent concentrations were monitored daily. The Type-1 experiment resulted in a source signature similar to that expected for a relatively well-mixed NAPL source, with dissolved concentrations dependent on chemical solubility and initial mass fraction. The Type-2 and Type-3 experiments were conducted for 320 d and 190 d respectively. Unlike the Type-1 experiment, the concentration vs. time behavior was similar for all chemicals, for both source types. The magnitudes of the effluent concentrations varied between the Type-2 and Type-3 experiments, and were related to the hydrocarbon source mass. A fourth physical model experiment was performed to identify differences between ideal equilibrium behavior and the source concentration vs. time behavior observed in the tank experiments. Screening-level mathematical models predicted the general behavior observed in the experiments. The results of these studies suggest that dissolved concentration vs. time data can be used to distinguish between Type-1 sources in transmissive zones and Type-2 and Type-3 sources in lower permeability zones, provided that many years to decades of data are available. The results also suggest that concentration vs. time data alone will be insufficient to distinguish between NAPL and dissolved-phase storage sources in lower permeability regions. / Dissertation/Thesis / M.S. Civil and Environmental Engineering 2014

M. Tech. / Relative to other industries in South Africa and construction industries worldwide, the South African construction process generates a disproportionate number of fatalities, injuries and disease, the direct and indirect cost of which contribute to the cost of construction. Serious accidents and injuries resulting in personal injury and wrongful death occur with alarming frequency at construction sites in the U.K. The majority of accidents are not caused by careless workers but rather by failure to control. According to the Health and Safety Executive report published in 1988 out of the 90% of all construction accidents leading to death 70% could have been prevented by positive management actions and interventiion. Clients influence construction health and safety performance. Architects and design engineers often disavow responsibility for health and safety issues associated with the construction of their work. Arguably, this denial will only change if clients insist that construction health and safety is addressed on their projects. Health and safety begins with the attitude that accidents are preventable and that requirements for healthy and safe work practices must be followed. Health and safety should not be left solely under the control of the workers if injuries are to be curtailed or diminished, because the health and safety environment consists of many factors over which workers have little or no control. An underlying belief is that the majority of accidents are not caused by careless workers but by failure in controls. Although the best site management of health and safety cannot prevent all accidents, entities other than those actually performing the work do have an important role to play in enforcing proper safety standard measures : It is possible to prevent accidents from occurring. Success in health and safety has a great deal to do with people, especially those who will be responsible for ensuring that the project will be delivered safely. There is some evidence that the importance of health and safety is being realised by clients. Costs associated with worker injuries and fatalities are borne ultimately by the client and insisting that health and safety be included in design and construction considerations will prevent the occurrence of injuries and ultimately reduce the construction costs. Clients mostly set health and safety culture during the construction phase. Health and safety prequalification criteria to design approval post the design phase that shows that clients would prefer their involvement to be in specific phases. Clients do not realise that they can make significant contributions to improve health and safety performance during the early stages of a project. Clients who have to pay for construction work do not make specific cost provision for construction safety. Clients need to afford health and safety the same status as other project parameters. It is widely accepted that contractors should bear the responsibility for health and safety during the construction phase. The study found that clients regarded the construction and maintenance phases as the most important to address health and safety. Again clients do not realise the significance of placing health and safety importance in the initial phases of a project.

No description available.

The purpose of this study was to develop a Web site for a primary school and to determine the quality of the web site in comparison with the web sites of other primary schools. The specific focus of this study was to determine the promotability of the web site and to point out the advantages for the school concerned. Ms Mariaan Greyvenstein, my co-researcher, focussed on the content development and management aspects of the web sites of primary schools. The dissertations of both the researchers discuss the web site of one specific school, and for this reason some information overlaps periodically. Both of the dissertations have separate functions and each one is special in its own way. A detailed description of the development and testing of the product is given. The acquisition and evaluation of results are discussed. The researcher discusses the findings to assure the profitability of the product. / Dissertation (MA (Information Science))--University of Pretoria, 2007. / Information Science / unrestricted

Nombre de programmes ont été développés pour identifier des sites de fixation de facteurs de transcription. La plupart ne sont pas capables d’inférer des motifs composés de deux mots en autorisant une variation de leur espacement, caractéristiques des sites de fixation des sous-unités s de l’ARN polymérase (SFFS). Cette thèse vise à l’élaboration d’un algorithme prenant en compte toutes les connaissances biologiques structurelles de ces sites en vue de leur prédiction fiable. Nous présentons une nouvelle approche, SIGffRid (pour SIGma Factor Finder using R’MES to select Input Data), pour l’identification des SFFS qui compare deux génomes bactériens phylogénétiquement apparentés. La méthode analyse des paires de régions promotrices de gènes orthologues. Elle utilise la sur-représentation statistiquement dans les génomes complets comme critère de sélection des boîtes -35 et -10 potentielles. Des motifs composites conservés sont alors groupés en utilisant des paires de courtes graines, en autorisant la variabilité de l’espacement qui les sépare. Les motifs sont ensuite étendus suivant des considérations statistiques. Les plus significatifs sont retenus. Cet algorithme a été applique´ avec succès à la paire de génomes bactériens apparentés de Streptomyces coelicolor A3(2) et Streptomyces avermitilis. Nous démontrons que notre approche, combinant des critères statistiques et biologiques, parvient à prédire des SFFS, et abordons les améliorations envisagées. / Many programs have been developed to identify transcription factor binding sites. Most of them are not able to infer two-word motifs with variable spacer lengths, characteristics of RNA polymerase Sigma (s) Factor Binding Sites (SFBSs). The aim of this thesis is to design an algorithm taking into account the biological structural observations about these sites, in order to their relevant prediction. We describe a new approach, SIGffRid (SIGma Factor binding sites Finder using R’MES to select Input Data), to identify SFBSs by comparing two related bacterial genomes. The method performs a simultaneous analysis of pairs of promoter regions of orthologous genes. SIGffRid uses a prior identification of over-represented patterns in whole genomes as selection criteria for potential -35 and -10 boxes. These patterns are then grouped using pairs of short seeds, allowing a variable-length spacer between them. This is followed by motif extension guided by statistical considerations. Finally, statitically feasible and relevant motifs are selected. We applied our method to the pair of related bacterial genomes of Streptomyces coelicolor A3(2) and Streptomyces avermitilis. We demonstrate that our approach combining statistical and biological criteria was successful to predict SFBSs, and envisage ameliorations.

Mechanistically and structurally chloroperoxidase (CPO) occupies a unique niche among heme containing enzymes. Chloroperoxidase catalyzes a broad range of reactions, such as oxidation of organic substrates, dismutation of hydrogen peroxide, and mono-oxygenation of organic molecules. To expand the synthetic utility of CPO and to appreciate the important interactions that lead to CPO’s exceptional properties, a site-directed mutagenesis study was undertaken. Recombinant CPO and CPO mutants were heterologously expressed in Aspergillus niger. The overall protein structure was almost the same as that of wild type CPO, as determined by UV-vis, NMR and CD spectroscopies. Phenylalanine103, which was proposed to regulate substrate access to the active site by restricting the size of substrates and to control CPO’s enantioselectivity, was mutated to Ala. The ligand binding affinity and most importantly the catalytic activity of F103A was dramatically different from wild type CPO. The mutation essentially eliminated the chlorination and dismutation activities but enhanced, 4-10 fold, the epoxidation, peroxidation, and N-demethylation activities. As expected, the F103A mutant displayed dramatically improved epoxidation activity for larger, more branched styrene derivatives. Furthermore, F103A showed a distinctive enantioselectivity profile: losing enantioselectivity to styrene and cis-β-methylstyrene; having a different configuration preference on α-methylstyrene; showing higher enatioselectivites and conversion rates on larger, more branched substrates. Our results show that F103 acts as a switch box that controls the catalytic activity, substrate specificity, and product enantioselectivity of CPO. Given that no other mutant of CPO has displayed distinct properties, the results with F103A are dramatic. The diverse catalytic activity of CPO has long been attributed to the presence of the proximal thiolate ligand. Surprisingly, a recent report on a C29H mutant suggested otherwise. A new CPO triple mutant C29H/C79H/C87H was prepared, in which all the cysteines were replaced by histidine to eliminate the possibility of cysteine coordinating to the heme. No active form protein was isolated, although, successful transformation and transcription was confirmed. The result suggests that Cys79 and Cys87 are critical to maintaining the structural scaffold of CPO. In vitro biodegradation of nanotubes by CPO were examined by scanning electron microscope method, but little oxidation was observed.

A new generation of Titanium based catalysts for ethylene polymerization has been developed through the Surface Organometallic Chemistry (SOMC) methodology using a novel type of silica support having a 3D fibrous morphology, KCC-1. The first type of Tibased catalyst was obtained by reacting isolated silanol surface groups, ≡SiOH of KCC-1 (dehydroxylated at 700 ⁰C under high vacuum, 10-5 bar) with titanium (IV) tetraneopentyl, Ti(CH2tBu)4 to produce [(≡SiO)Ti(CH2tBu)3]. The second type of Ti-based catalyst was generated by using an Al-modified KCC-1. The peculiarity of this support is due to the presence of tetra-coordinated aluminum-bound hydroxyl group, [(≡Si-O-Si≡)(≡SiO)2Al- OH] that can be used as a Lewis Acid anchor sites and generate new catalytic properties. The well-defined [(≡Si-O-Si≡)(≡SiO)2Al-OH] was obtained by reacting diisopropylaluminum hydride with KCC treated at 700 °C followed by a thermal treatment at 400 °C and oxidation with N2O. IR spectra of pyridine adsorbed on the Al sites show that these were strong Lewis acid sites (constituting 80% of the total Al sites). Thus, the highly electrophilic support surface was used to create a single well-defined surface organo-titanium fragment [(≡Si–O–Si≡)(≡Si–O–)2Al–O–Ti(CH2tBu)3] by the reaction of the surface [(≡Si–O–Si≡)(≡Si–O)2Al–OH]) groups with Ti(CH2-tBu)4 at room temperature for 4 h in dry pentane. The performance of each Ti-supported catalyst assessed for ethylene polymerization. It was found that Al-modified support (highly electrophilic) provide better activity compared to the unmodified one. Indeed, the productivity of the catalyst [(≡Si–O– Si≡)(≡Si–O–)2Al–O–Ti(CH2tBu)3] was found to be 67.8 g of PE/ 1mmol Ti/ 1h with molecular weight of 3208408 g/mol; polydispersity was found to be 2.3, and (HDPE) high-density polyethylene was obtained. In contrast, [(≡SiO)Ti(CH2tBu)3] (unmodified one) produces lower molecular weight polymer 989843 g/mol, higher polydispersity (PD) 6.7 and low-density polyethylene (LDPE) productivity was found to be 14.670 g PE/1mmol Ti /1h. These results demonstrate that modification of the oxide ligands on silica through a generation of Al Lewis acid site opens up new catalytic properties, markedly enhancing the catalytic performance of supported organotitanium species. We also demonstrate how the silica mesostructure (2D vs 3D ) affects the catalytic activity in ethylene polymerization. While SBA15 (2D) could limit the accessibility of the active sites resulting in lower yield. In contrast, KCC-1 (3D) are more active in ethylene polymerization, because the active sites reside on the external surface are fully accessible to the substrate.

Managers of historic sites need to understand their exposure to climatic and environmental change, which varies widely by property type and location. A large and evolving body of science and climate modeling identifies ongoing and future changes with increasing specificity. Changes range from the predictable, like mean temperature and sea-level rise, to the erratic, like storms and wildfires, and may include human adaptive measures like floodwalls and migration. These data can be cross-referenced against site attributes to evaluate risk. Relevant site attributes include location and topography, materials, character-defining features, landscape species, surrounding land uses, and operational needs. This work presents a vulnerability assessment protocol that serves to identify and rank risk in order to inform decision-making about adaptive measures, which can range from choice of repair materials to landscaping to relocation. When applied to a fleet of sites, the protocol can inform policy- and grant-making. / 1 / SPK / archives@tulane.edu

The immunologic relatedness of various cofactor-binding sites of enzymes requiring different nucleotide cofactors was examined. Chicken antibodies specific for NADPH- or CoA-binding domains were raised using an NADPH- or CoA-requiring enzyme as an immunogen. Antibodies specific for either NADPH- or CoA-binding domains were isolated by immunoaffinity chromatography of the respective antisera using unrelated NADPH- or CoA-requiring enzymes as affinity ligands. The reactivities of the NADPH- and CoA-binding-site-specific antibodies with a variety of enzymes that required different cofactors was shown on Western blots of SDS-PAGE of the enzymes. Variable cross-reactivities were observed among all nucleotide-cofactor requiring enzymes with each specific cofactor-domain-antibody population. Numerous proteins not physiologically associated with nucleotide cofactors, including acyl carrier protein, were completely unreactive. Proteins that bound phosphoryl compounds either as substrates or cofactors showed varying degrees of reactivity with each population of specific antibodies. These included aldolase, ribulose-1,5-bisphosphate carboxylase/oxygenase, ribonuclease A, carbonic anhydrase and triosephosphate isomerase. The immunologic cross-reactivity suggested that these proteins share a common structural feature, probably a primary structure epitope, since the proteins had been subjected to denaturing polyacrylamide gel electrophoresis. A candidate for this common structural feature is a glycine-rich sequence comprising a phosphate binding loop.

There has been limited research regarding teachers' opinions about their involvement in school decision making. A critical step missing in the research is the development of instruments to assess teachers' perceptions of their actual and desired levels of involvement. With the wide spread use of site-based management, shared decision making, participatory management and teacher empowerment, it is important to study teachers' involvement. The purpose of this study was to design an instrument to measure teachers' satisfaction with their involvement in school decision making. A review of the literature was used to identify issues to be considered for instrument development. Four domains were formulated for the Satisfaction with Participation in Decision Making Questionnaire (SPDMQ): (1) Involvement in the Operation of the School; (2) Involvement in Establishing Curriculum and Instructional Techniques; (3) Teacher Development, Evaluation, and Work Allocation, and (4) Involvement in Establishing Student Teacher Relationships. There are five questions included in each domain, for a total of 20 questions. Each question measures a desired level of involvement and a perceived actual level of involvement in school decision making. To measure content and construct validity, a total of three draft instruments were administered to doctoral students, school administrators, teachers, and other educators. The population selected to validate the instrument consisted of all teachers in five elementary schools from two different school districts in the Hampton Roads area. Two schools were selected from a district that currently implements site-based management programs, and three schools were selected from a district that implements little or no site- based management. A total of 168 teachers completed the SPDMQ. The treatment of data included several statistical routines including chi-square, Cronbach's alpha, t-tests, and correlations. The results of administration of the SPDMQ indicated that teachers in site-based schools reported more involvement in decision making but were not significantly more satisfied with their involvement. This instrument may be used by principals as a needs assessment to determine how much and in what areas teachers want to be involved in school decision making. / Ed. D.