Previous studies have suggested that iron PRBs, receiving high concentrations of inorganic constituents in groundwater, may experience passivation because of the accumulation of inorganic precipitates. In an iron PRB containing more highly reactive material, even though the initial contaminant removal rate is faster than for less reactive material, a faster migration of the contaminant removal front may occur due to the greater reactivity loss, caused by faster accumulation of secondary precipitates. In contrast, an iron PRB containing less reactive material may show a slower accumulation of precipitates, and thus will show a slower migration of the contaminant removal front over time. Thus, it is hypothesized that an iron material having moderate initial reactivity may be more advantageous than material having a higher reactivity in terms of long-term performance. The objective of this study was to test this hypothesis by evaluating the changes of the reactivities of different iron materials in the presence of dissolved CaCO₃. <br /><br /> Four different iron materials (Connelly, G-M, Ispat and Peerless) were selected for the column experiments. The changes in reactivities of the iron and formation of secondary precipitates over time were assessed, primarily by the iron corrosion rates, calculated from the hydrogen gas generation rates, by the cis-DCE removal rates and by the alkalinity profiles. The accumulation of precipitates in the four columns caused passivation of the iron. The passivation of the iron in turn resulted in migration of the mineral precipitation fronts as well as profiles of cis-DCE, TCE, VC, alkalinity, Eh, pH, and chloride. Connelly and G-M had longer periods of operation than Ispat and Peerless and thus their performance was the primary test of the hypothesis. G-M iron, which had the higher initial corrosion rate, compared to Connelly, showed a faster accumulation of precipitates near the influent end. The difference in accumulated precipitates resulted in a difference in the leading edge of the organic profiles and a significant difference in the pattern of passivation, indicating a faster passivation in the region near the influent end for G-M. <br /><br /> Model simulations were performed using the same fitting parameters but with different initial corrosion rate constants to further test the hypothesis. The model provided a reasonable representation of changing reactivities of the columns, being consistent with the observed data. In the simulation for long-term prediction, the cases of higher corrosion rates showed earlier breakthroughs and steeper curves than those of lower corrosion rates. Also, the predictions showed greater porosity loss for the case of higher corrosion rate. Thus, long-term predictions support the hypothesis. Accurate determination of model parameters such as cis-DCE degradation rate constants and iron corrosion rates are required for better predictions of long-term performance.

The purpose of this dissertation was to explore the experience of long term grief following a perinatal loss. In particular, the processes of meaning reconstruction and self-changes stemming from perinatal loss were explored by listening to parents in-depth narratives of their experiences of loss and grief. A narrative methodology was used, based on a constructivist epistemology that suggests that people are storytellers by nature and we attempt to organize and make sense of our life experiences by constructing coherent narratives. Participants were 4 couples and 8 individuals whose losses occurred 1 to 35 years before the interview. Interviews followed a reflexive-dyadic interview model. Analysis of the narratives was approached in two ways: First, a voice-centered relational approach was used for initial interpretation and identification of prevalent voices in the stories. Second, five of the stories were written as evocative narratives, which served as a way of incorporating the authors personal experience of perinatal loss, as well as to evoke an empathic understanding of the experience of perinatal loss. The interpretation and discussion of the stories focused on meaning-making that was evident on both an individual level as well as across the larger group of participants. In particular, meaning-making influences and strategies were identified, including influences of the medical establishment and social networks which either served to disenfranchise parents losses or to comfort and ease parents in their grief. The impact of meaning-making on long-term grief was considered, as well as parents reports of positive and negative self-changes that emerged from their struggle with grief. The unique contribution of this project lies in its elaboration of the meaning reconstruction process in the context of perinatal loss; its demonstration of both positive and negative self-changes in a group of perinatally-bereaved parents; its exploration of grief several years to decades following a perinatal loss; its inclusion of the researchers self as both an additional source of data and as a validity check on the presentation and interpretation of participants stories; and the use of evocative narratives to evoke an empathic understanding of a historically disenfranchised form of loss.

Past research advocates the need for long-term care (LTC) facilities to adopt a person-centred model of care to optimize residents quality of life. The construct of quality of life in LTC has been defined by satisfaction with a set of domains identified by Kane and colleagues (2003). One goal of this study was to determine which domain is the most predictive of overall well-being among LTC residents in a rural setting. Based on past research and on Deci and Ryans (1985; 1991) self-determination theory, satisfaction with autonomy was predicted to emerge as most predictive of overall well-being. The present study also examined the relation between resident quality of life and well-being, and the degree of routinization (i.e., adherence to a rigid, inflexible daily schedule) within the LTC environment. Routinization is conceptually at odds with a person-centred model of care, yet its relation to the well-being of care recipients had not been examined prior. One hundred and ninety-eight residents from 15 LTC facilities in rural Saskatchewan participated in individual interviews to measure their satisfaction with 11 quality of life domains (Kane et al., 2003), and their overall well-being (using the Memorial University of Newfoundland Scale of Happiness; MUNSH; Kozma & Stones, 1980). One hundred and thirty-one staff from the 15 facilities completed a questionnaire designed to assess routinization within the LTC environment. Contrary to predictions, autonomy failed to emerge as a significant predictor of overall well-being among sample residents. The domain of meaningful activity received residents lowest satisfaction rating of the 11 domains, and also accounted for the most unique variance in overall well-being. Routinization was negatively related to resident quality of life, with staff rating routinization higher in facilities which residents reported lower satisfaction with quality of life. Results provide focus for improving the quality of life of LTC residents, and point to areas for further study.

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Background: The Internet has created new efficient channels of doing business. For this nontraditional market, a business strategy that is both effective and efficient needs to be employed. The Long Tail business strategy was developed by Chris Anderson in 2006. It is possible that the Long Tail strategy not only can increase revenue by offering more “niche” products, but also can enhance customers’ loyalty toward the company. However, in order to achieve the latter, companies need to communicate with customers in more effective and more efficient ways. Therefore, communication is inevitably the fundamental element for companies’ efforts to build customer relationships. The Long-Tail, suggested by Anderson and Sugaya, to be an effective strategy for enhancing customer loyalty. But can it fit in the case of Swedish Apple Premium Resellers?   Purpose: The purpose of this thesis is to test if the Long-Tail strategy can enhance e-loyalty by adding value to online marketing communications in the case of Apple Premium Resellers’ customers in Sweden. Method: The data collection was mainly through questionnaires -- a quantitative approach. The target group was Apple Premium Resellers’ customers in Sweden. The questionnaire was distributed in Stockholm and Jönköping. Various statistical techniques as well as theories and models were used for data analysis. Conclusion:It can be concluded that the Long Tail strategy can add value to the online marketing communications, and improved online marketing communications can enhance customer loyalty in e-commerce. Therefore, the Long-Tail strategy can enhance e-loyalty by adding value to online marketing communications in the case of Swedish Apple Premium Resellers.

The polluted agricultural wastewater, after reaching marine recipients, can cause eutrophication. This problem can be tackled and mitigated by using constructed wetlands as water treatment systems. The fact that constructed wetlands work through long periods of time has led many scientists to evaluate how long they can still treat their influents effectively. The development and growth of vegetation and the accumulation of nutrients on the soils in a wetland are expected to occur. These processes change the wetland efficiency to remove pollutants. In this study, a set of wetlands constructed to treat agricultural wastewater were analyzed in different periods to assess if there is a difference in removal efficiency of nitrogen and phosphorus. This assessment was performed by analyzing the retention rate, k and k20 values, which are variables that quantify the nutrients removal, in different periods of each employed wetland. Some of the observations demonstrated differences when comparing different periods of the wetlands. The nitrogen removal presented better performance in one of the employed wetlands when this was older. Another employed wetland has not shown a clear difference between different periods. In the wetlands with high vegetation densities, the nitrogen removal was more stable over consecutive years. The occurrence of oscillations in nitrogen removal was observed more often in the wetlands with the highest vegetation densities over consecutive years. The phosphorus removal presented no clear differences between different periods. The results suggest that the removal of nitrogen improves after wetland creation due to the growth of vegetation. In addition, they suggest that wetlands with high vegetation densities tend to oscillate the nitrogen removal more or less often according to the density of the vegetation due to the balance between denitrification and decomposition. Further, the results suggest that the removal of phosphorus remains unchanged over longer periods than the periods considered in this study (four to six years) due to the deposition of organic matter on the soils.

<p>I characterize optimal long term contracts offered by a monopolist to a buyer whose private valuation evolves according to a branching process with privately known transition probability. The optimal contract can be implemented in a simple way, and presents the buyer with a tradeoff between a high initial fixed fee and low future prices. In an interaction with a long time horizon, the relationship will terminate prematurely with probability close to one. Optimal mechanisms are quite different from models in which the transition probability is known, and the buyer's private information is his initial valuation. Optimal contracts resemble the structure of term life insurance contracts, and have features similar to actual interactions between retailers and suppliers.</p> / Dissertation

<p>The central puzzles in financial economics commonly include</p><p>violations of the expectations hypotheses, predictability of excess returns, and the levels and volatilities of nominal bond yields, in addition to well-known equity premium and the risk-free rate puzzles.</p><p>Equally surprising is the recent evidence on large moves in asset prices, and the over-pricing of the out-of-the-money index put options relative to standard models. In this work, I argue that the long-run risks type model can successfully explain these features of financial markets. I present robust empirical evidence which supports the main economic channels in the model. Finally, I develop econometric methods to estimate and test the model, and find that it delivers plausible preference and model parameters and provides a good fit to the asset-price and macroeconomic data.</p><p>In the first chapter, which is co-authored with Ravi Bansal, we present a long-run risks based equilibrium model that can quantitatively explain the violations of expectations hypotheses and predictability of returns in bond and currency markets. The key ingredients of the model include a low-frequency predictable component in consumption, time-varying consumption volatility and investor's preferences for early resolution of uncertainty. In this model, varying consumption volatility in the presence of the predictable consumption component leads to appropriate variation in bond yields and the risk premia to provide an explanation for the puzzling violations of the expectations hypothesis. Using domestic and foreign consumption and asset markets data we provide direct empirical support for the economic channels highlighted in the paper.</p><p>In the second chapter, co-authored with Ravi Bansal, we develop a general equilibrium model in which income and dividends are smooth, but asset prices are subject to large moves (jumps). A prominent feature of the model is that the optimal decision of investors to learn the unobserved state triggers large asset-price jumps. We show that the learning choice is critically determined by preference parameters and the conditional volatility of income process. An important prediction of the model is that income volatility predicts future jumps, while the variation in the level of income does not. We find that indeed in the data large moves in returns are predicted by consumption volatility, but not by the changes in the consumption level. In numerical calibrations, we show that the model can quantitatively capture these novel features of the data.</p><p>In the third chapter, I present a long-run risks type model where consumption shocks are Gaussian, and the agent learns about unobserved expected growth from the cross-section of signals. The uncertainty about expected growth (confidence measure), as in the data, is time-varying and subject to jump-like risks. I show that the confidence jump risk channel can quantitatively account for the option price puzzles and large moves in asset prices, without hard-wiring jumps into consumption. Based on two estimation approaches, the model provides a good fit to the option price, confidence measure, returns and consumption data, at the plausible preference and model parameter values.</p> / Dissertation

Today, the Internet is growing exponentially, with traffic statistics that mathematically exhibit fractal characteristics: self-similarity and long-range dependence. With these properties, data traffic shows high peak-to-average bandwidth ratios and causes networks inefficient. These problems make it difficult to predict, quantify, and control data traffic. In this thesis, two analytical methods are used to study fractal network traffic. They are second-order self-similarity analysis and multifractal analysis. First, self-similarity is an adaptability of traffic in networks. Many factors are involved in creating this characteristic. A new view of this self-similar traffic structure related to multi-layer network protocols is provided. This view is an improvement over the theory used in most current literature. Second, the scaling region for traffic self-similarity is divided into two timescale regimes: short-range dependence (SRD) and long-range dependence (LRD). Experimental results show that the network transmission delay separates the two scaling regions. This gives us a physical source of the periodicity in the observed traffic. Also, bandwidth, TCP window size, and packet size have impacts on SRD. The statistical heavy-tailedness (Pareto shape parameter) affects the structure of LRD. In addition, a formula to estimate traffic burstiness is derived from the self-similarity property. Furthermore, studies with multifractal analysis have shown the following results. At large timescales, increasing bandwidth does not improve throughput. The two factors affecting traffic throughput are network delay and TCP window size. On the other hand, more simultaneous connections smooth traffic, which could result in an improvement of network efficiency. At small timescales, in order to improve network efficiency, we need to control bandwidth, TCP window size, and network delay to reduce traffic burstiness. In general, network traffic processes have a Hlder exponent a ranging between 0.7 and 1.3. Their statistics differ from Poisson processes. From traffic analysis, a notion of the efficient bandwidth, EB, is derived. Above that bandwidth, traffic appears bursty and cannot be reduced by multiplexing. But, below it, traffic is congested. An important finding is that the relationship between the bandwidth and the transfer delay is nonlinear.

ABSTRACT As the population ages and family structure changes quickly, the demand for long-term care services from elderly people increased rapidly. In the aboriginal villages, due to insufficient medical sources, weak economic condition, and lack of young manpower in family, the need of aboriginal elderly people for health care is much more than urban residents. The study field located in Pingtung County is because it is the territory has the most indigenous townships in Taiwan. The study mainly adopts qualitative methodology with small amount of questionnaires to conduct quantitative analysis, it is expected to draw different dynamic result to generate useful outcome. Based on the findings and conclusion after collected and analyzed, the research could provide reference for the development of long-term care project in aboriginal area and long-term caring insurance in future. The research found that the county government and execution organization- NPO both built positive partnership, but the administration of indigenous people and local township office are not involved much. In additional, the provisions of caring health elder in community between Ministry of the interior and Council of indigenous people are duplicated. The users decreased significantly after implementation of users¡¦ pay concept for additional service hours, and it also caused aboriginal women who work as caregiver lost their jobs. In terms of service utilization, the top three services are body clean, house service and mental support, and the result of questionnaires presents great satisfaction. However, considering of weak economic condition, the elderly cannot accept self-afford service yet. Conclusion: 1. Government should adjust different users¡¦ pay level for isle and indigenous township. 2. It should integrate duplicated resources of community-base for health elderly people. 3. Home caregiver can play role of a propagator for welfare and health care policy in village. 4. To develop an integrated long-term care information system to improve the efficiency of case management and service resource.