Coastal counties make up only 17% of the land area in the continental United States, yet 53% of the nation’s population resides in these locations. With sea level rise, erosion, and human disturbances all effecting coastal areas, researchers are working to find strategies to protect and stabilize current and future shorelines. In order to maintain shoreline stability while maintaining intertidal habitat, multipurpose living shorelines have been developed to mimic natural shoreline assemblages while preventing erosion. This project determined the effectiveness of a living shoreline stabilization containing Crassostrea virginica (eastern oyster) and Spartina alterniflora (smooth cordgrass) in the field and through controlled wave tank experiments. First, fringing oyster reefs constructed of stabilized oyster shell and smooth cordgrass plugs were placed along three eroding shoreline areas (shell middens) within Canaveral National Seashore (CANA), New Smyrna Beach, FL. For each shell midden site, four treatments (bare shoreline control, oyster shell only, S. alterniflora only, and oyster shell + S. alterniflora) were tested in replicate 3.5 x 3.5 meter areas in the lower and middle intertidal zones. Each treatment was replicated five times at each site; erosion stakes within each replicate allowed measurement of changes in sedimentation. After one year in the field, the living shoreline treatments that contained oyster shells (oyster shell only and oyster shell + S. alterniflora) vertically accreted on average 4.9 cm of sediment at two of the sites, and an average of 2.9 cm of sediment at the third, while the controls lost an average of 0.5 cm of sediment. S. alterniflora did not significantly contribute to the accretion at any site due to seagrass wrack covering and killing plants within one month of deployment. Next, the reduction in wave energy caused by these living shoreline stabilization techniques relative to bare sediment (control) was quantified. The energy reduction immediately after deployment, and the change in energy reduction when S. alterniflora had been allowed to grow for one year, and the stabilized shell was able to recruit oysters for one year was tested. Laboratory experiments were conducted in a nine-meter long wave tank using capacitance wave gauges to ultimately measure changes in wave height before and after treatments. Wave energy was calculated for each newly deployed and one-year old shoreline stabilization treatment. Boat wake characteristics from CANA shorelines were measured in the field and used as inputs to drive the physical modeling. Likewise, in the wave tank, the topography adjacent to the shell midden sites was measured and replicated. Oyster shell plus S. alterniflora attenuated significantly more wave energy than either the shells or plants alone. Also, one-year old treatments attenuated significantly more energy than the newly deployed treatments. The combination of one-year old S. alterniflora plus live oysters reduced 67% of the wave energy. With the information gathered from both the field and wave experiments, CANA chose to utilize living shorelines to stabilize three shell middens within the park. Oyster shell, marsh grass and two types of mangroves (Rhizophora mangle, Avicennia germinans) were deployed on the intertidal zones of the eroding middens. Significant accretion occurred at all middens. Two sites (Castle Windy and Garver Island) vertically accreted an average 2.3 cm of sediment after nine months, and six months respectively, and the other site (Hong Kong) received on average 1.6 cm of sediment after six months. All control areas (no stabilization) experienced sediment loss, with erosion up to 5.01 cm at Hong Kong. Plant survival was low ( < 20%) at Castle Windy and Garver Island, while Hong Kong had moderate survival (48-65%). Of the surviving marsh iv grass and mangroves on the three sites, almost all ( > 85%) had documented growth in the form of increased height or the production on new shoots. Landowners facing shoreline erosion issues, including park managers at CANA, can use this information in the future to create effective shoreline stabilization protocols. Even though the techniques will vary from location to location, the overall goal of wave attenuation while maintaining shoreline habitat remains. As the research associated with the effectiveness of living shorelines increases, we hope to see more landowners and land managers utilize this form of soft stabilization to armor shorelines.

The presence of nitrates and phosphorus in ground water is a worldwide problem. A septic tank with drainfield that is conventionally designed does not typically remove nitrogen in the form of nitrates. The main risks are in "Blue baby" syndrome and suspected carcinogenic effect of nitrates on humans and the nutrient enrichment of receiving waters. In some areas nitrate and phosphorus removal are essentially required. Thus the information in this report concentrates on using media in the drainfield for the removal of nitrogen and phosphorus. Extensive work has been conducted in the past few decades in order to find suitable media for denitrification with high selectivity towards nitrogen. Column experiments were conducted at the University of Central Florida to simulate the actual septic tank drainfield using mixes of fine sand. In one of the columns Sawdust and Tire Crumb were added to the Sand (STS) and in the other column Paper and Tire Crumb were added to the Sand (STP). Tire crumb was added as a carbon source required for better denitrification and for sorption. The columns were dosed daily using regular septic tank effluent and it was a continuous batch system. Samples were taken after a hydraulic retention time (HRT) of 24 hours and comparisons were made of the effluent with the influent to show percentage removal of nitrogen (nitrates, ammonia and total nitrogen), phosphorus (ortho-phosphorus and total phosphorus) and BOD. STS and STP columns showed more than 90% removal for all parameters (nitrates, ammonia, total nitrogen, ortho-phosphorus, total phosphorus, BOD). The results indicate that the investigated media blend (Black and GoldTM Nugget Mix) has the potential for successful application in full scale operations. It is recommended that Black and GoldTM Nugget Mix be used to achieve the required removal of the nutrients.

An introduction is given to the background theory and scientific literature of the major subject areas of interest in this thesis, namely the chemistry of free radical and anionic polymerisation, molecular weight control in each type of polymerisation, polymerisation reactors, computer simulation of polymerisation processes and polymer characterisation by gel permeation chromatography. A novel computer model has been devised, based on the analysis of the polymerisation process in terms of the reaction extent of each reactant and the use of generation functions to describe the concentration of living and dead polymeric species, for the free radical, solution polymerisation of methylmethacrylate in a CSTR. Both heat and mass balance expressions have been described. Conversion, Mn and Mw were monitored. To test the model a reactor was designed and constructed. A detailed description of the reactor and the experimental conditions used for the validation of the model are given. The results of these studies are presented and excellent agreement is shown between model predictions and experiments up to 30% conversion for Mn w and % conversion. A similar study is described for the anionic polymerisation of styrene in tetrahydrofuran as solvent, in a CSTR. In this work the computer model becomes 'stiff' when realistic rate constants are introduced in the kinetic expressions. Experimental difficulties were encountered in obtaining reproducible results in the anionic work. A new approach of using 'scavengers' as protecting agents for the living chains is described. A scavenger was successfully employed in the preparation of block copolymers using a tubular reactor. Block copolymerisation, in addition to providing a means of checking the number of the 'living' chains inside the reactor, is of interest in its own right. All the experimental findings are discussed in relation to the currently accepted views found in the scientific literature.

Here the nature of gas phase processes and their implications for flow and transport were examined using a pilot-scale, 2-dimensional, laboratory tank instrumented for direct, in situ trapped gas measurements. Experimental conditions mimicked an unconfined, homogeneous sand aquifer with horizontal flow. Key areas of investigation included i) trapped gas dissolution following a water table fluctuation; and ii) gas phase dynamics within a hydrocarbon plume experiencing dissolved gas production via biodegradation. In the first experiment, dissolution occurred as a diffuse, wedge-shaped front propagating down-gradient in the tank over time, with enhanced dissolution at depth. Front advancement at the deepest monitoring point was 4.1 - 5.7x faster. This dynamic, depth-dependent pattern was mainly attributed to increased dissolved gas solubility. An estimated 12% increase in quasi-saturated hydraulic conductivity (Kqs) also contributed to greater dissolution at depth. Overall, the dissolution front near the water table advanced 1 m down-gradient in 344 days, suggesting that gas trapped shallowly will likely persist for significant periods of time. The utility of total dissolved gas pressure sensors for simple in-well measurements to detect trapped gas and monitor its dissolution were also demonstrated. During the second experiment, biodegradation occurred under variable redox conditions, ranging from denitrification to methanogenesis. Significant in situ increases in trapped gas were observed within the tank over 330 days. Maximum gas saturations never exceeded 27% of pore volume even during continued dissolved gas production, indicating ebullition upon reaching a gas phase mobilization threshold. Consequently, associated reductions in Kqs were restricted to a factor of 2 or less, but still appeared to alter the groundwater flow field. While trapped gas increases within the biodegradation plume were expected, declines in gas saturations were also observed. Thus, the overall pattern of trapped gas growth exhibited high spatial and temporal variability. Influencing factors included changes in hydrocarbon inputs and microbial controls on redox zonation, in addition to ebullition and changes in groundwater flow; emphasizing that gas phase growth in contaminant plumes will be highly complex and dynamic in the natural systems. Given the impacts on hydraulic conductivity, and the fate and transport of volatile compounds, an improved understanding of quasi-saturated conditions will be beneficial for various groundwater applications, from recharge and paleoclimate studies to site characterizations and remediation strategies. / Dissertation / Doctor of Philosophy (PhD)

An optimal stochastic feedforward-feedback control scheme is implemented on a heat exchanger-stirred tank system using an on-line minicomputer. Because variations in the measured disturbance variable have an effect on the output controlled variable before compensating action can become effective, the feedforward action must be predictive in nature. Statistical time series models are used to model both the measured disturbance and the unobserved disturbances in the system. These stochastic disturbance models and the transfer function models for the process are identified, fitted and checked using statistical model building procedures on a set of data collected on-line using the minicomputer. The predictive feedforward-feedback controller is derived from these models. The performance of the control scheme is compared with that of a pure feedback control scheme and the actual performances are shown to conform well to the theory. / Thesis / Master of Engineering (ME)

The purpose of research - to identify the distinctive features of management of analytical centers, affecting the work of improving the competitiveness of organizations. The object of the study is analytical centers in Russia and abroad. The subject of the study are the factors influencing the increase of competitiveness of think tanks. Think tanks perform a wide range of tasks involved in research and consulting in the field of social policy, political strategy, economy, militarization, technology and culture. In addition to commercial activities, they fulfill an important political role, creating a dialogue between public authorities, the academic community and civil society organizations, as well as the two largest world centers of research organizations in the field of economic policy is the United States and the European Union, which formed sector analytical centers, While in Russia, they are just beginning to separate segments organizations. / Цель исследования – определить отличительные особенности управления аналитическими центрами, влияющие на повышение конкурентоспособности работы таких организаций. Объектом исследования выступают аналитические центры России и зарубежных стран. Предметом исследования являются факторы, влияющие на повышение конкурентоспособности аналитических центров. Аналитические центры выполняют широкий набор задач, занимаются проведением исследований и консалтингом в области социальной политики, политической стратегии, экономики, милитаризации, технологий и культуры. Помимо осуществления коммерческой деятельности, они выполняют важную политическую роль, создавая диалог между органами государственной власти, академическим сообществом и гражданскими организациями, а также двумя крупнейшими мировыми центрами исследовательских организаций в области экономической политики являются Соединенные Штаты и Евросоюз, в которых сформирован сектор аналитических центров, в то время как в России их только начинают выделять в отдельный сегмент организаций.

<p> </p> <p>Over the last few years, there has been a concerted effort to develop and validate models<br> aiding the development of cryogenic refueling technologies. This effort is focused on the goal<br> of one day being able to refuel and store cryogenic propellants in the low gravity environ-<br> ment of space. The purpose of this research is to leverage the capabilities of some of these<br> recently developed models to create new ones and model more phenomena related to the<br> space applications of cryogenics.<br> The modelling work presented here is focused in the areas of cryogenic tank chilldown<br> and tank pressure control during storage/transfer. These tools are meant to help inform<br> future experiments being performed at the Glenn Research Center and elsewhere.<br> The model focusing on cryogenic tank chilldown provides a transient approach using<br> the charge-hold-vent (CHV) methodology to calculate the mass and time required to chill<br> a tank down to a desired temperature. Building on the 1-g Universal No-Vent Fill model<br> developed by NASA, the model captures the flashing of pooling liquid during the rapid<br> de-pressurization caused during the vent stage of the chilldown process. The model is com-<br> pared against two different datasets and successfully predicts pressure response throughout<br> the process to within 22%.<br> The thermodynamic vent system (TVS) model has been designed to be seamlessly inte-<br> grated into the 1-g Universal No-Vent Fill model to predict condensation and heat transfer<br> provided by the TVS during a no-vent fill. The TVS coil is spatially discretized and the<br> axial temperature distribution solved for. The model is capable of adapting to a rapidly<br> lowering or rising fill level that can lower the overall heat removal provided by the TVS.<br> While the heat removal is of primary importance, by capturing secondary phenomena such<br> as two-phase pressure drop, the TVS model is also capable of informing design decisions for<br> future systems. The model is compared against three test cases and predicts heat removal<br> to within 2%.<br> <br> </p> <p> </p>

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