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An innovative method has been developed for synthesizing aluminum-aluminum nitride nanocomposite materials wherein the reinforcing nano-sized aluminum nitride particles are formed in-situ in a molten aluminum alloy. This method, which circumvents most issues associated with the traditional ways of making nanocomposites, involves reacting a nitrogen-bearing gas with a specially designed molten aluminum alloy. The method ensures excellent dispersion of the nanoparticles in the matrix alloy, which is reflected in enhanced mechanical properties. In this thesis, the author reviews the limitations of the conventional methods of manufacturing nanocomposites and develops thermodynamic and kinetic models that allow optimizing the in-situ gas-liquid process to produce quality nanocomposite material. Also, in this thesis, the author reports the measured room temperature and elevated temperature tensile properties of materials that were made by the optimized process and compares the measured values to their counterparts obtained for the base alloy. A 75 pct. increase in room temperature yield strength is obtained when the base alloy is reinforced with one pct. nano-size aluminum nitride particles and this significant increase in yield strength is accompanied by only negligible loss of ductility.

The dropout rate for many Mississippi high schools has improved tremendously over the last decade. In 2017, the Mississippi Department of Education reported that the dropout rate for the State declined form 13.9% to 10%. This rate was only 4% higher than the national average. However, with all the research that pertains to student dropouts and the success many states are seeing, there are still school districts failing to show improvement. Many high schools have dropout rates in excess of 20%. This study explored the perceptions of district high school principals, counselors, and other administrators working in schools with students who are at risk of dropping out. It examined the prevention practices or strategies that are the most effective in improving dropout rate conditions. The theoretical framework of this study was the theory of experience and experiential learning theory addressed by Dewey, Neill, and Kolb. Dewey (1916) argued that students could not control their previous experiences, but once a student understood the importance of engaging in the learning and the implications of persisting in school they could then take ownership of their learning and succeed. The importance of this involved student motivation and engagement. Kolb (1984) further developed this theory with the concept of a student’s learning style to help individuals identify the way they learn from experience. Hence, helping students engage in learning by internalizing its value to students remained a primary concept. Data collection methods included surveys, interviews, and a review of participating school’s dropout prevention plans. The results of this study indicated that successful schools are using dropout prevention plans which may be emulated or duplicated in other schools. The components of such plans are directly connected to the themes that emerged from successful school leaders regarding student persistence in high school. The study found that key elements for a successful program included the following: community collaborations, leadership development, teaching and learning practices, and support from district level leadership. It was determined that the administrators and counselors believed that they were capable of meeting the needs of their students through various programs, district initiatives, teacher and leadership development, and the involvement of all stakeholders which were the leading factors to their success. All of these elements were required in order to see substantive gains in student dropout rate.

OBJECTIVE: Simulation offers an important avenue for surgical and anesthesia training. This is especially important for crisis management scenarios where individuals need to act quickly and efficiently for optimal patient care. Practice based performance can be measured and real time feedback provided during debriefing scenarios. METHODS: In this paper, we highlight a dual anesthesia and otolaryngology cavernous carotid injury scenario. The trials were run three different times with inter-trial debriefing. RESULTS: The focused debriefing improved resident performance in terms of blood loss on subsequent trials. Furthermore, the learners provided important feedback regarding the utility of training and how it improved their ability to handle crisis management scenarios in the future. CONCLUSION: Debriefing for crisis management in a simulation trial improves performance and trainee confidence. Follow up studies will evaluate real world effectiveness over a longer follow up period.

Public agricultural research has been conducted in Africa for decades and has generated numerous crop technologies, while little is understood on how agricultural research affects the poor and vulnerable groups such as children, and how farmers' perceptions affect their adoption decisions. This dissertation helps fill this gap with three essays on adoption and impacts of improved maize varieties in rural Ethiopia. The first essay estimates poverty impacts. Field-level treatment effects on yield and cost changes with adoption are estimated using instrumental variable techniques, with treatment effect heterogeneity fully accounted for in marginal treatment effect estimation. A backward derivation procedure is then developed within an economic surplus framework to identify the counterfactual income distribution without improved maize varieties. Poverty impacts are estimated by exploiting the differences between the observed and counterfactual income distributions. Improved maize varieties have led to 0.8-1.3 percentage drop in poverty headcount ratio and relative reductions in poverty depth and severity. However, poor producers benefit the least from adoption due to their small land holdings. The second paper assesses the impacts on child nutrition outcomes. The conceptual linkage between maize adoption and child nutrition is first established using an agricultural household model. Instrumental variable (IV) estimation suggests the overall impacts to be positive and significant. Quantile IV regressions further reveal that such impacts are largest among the most severely malnourished. By combining a decomposition procedure with estimates from a system of equations, it is found that the increase in own-produced maize consumption is the major channel such impacts occur. The third paper explores how farmers' perceptions of crop traits affects their willingness to adopt improved maize varieties. Under a random utility framework, a mixed logit procedure is implemented to model farmer's adoption intention, where perceptions of key varietal traits are first identified, and then instrumented using a control function approach to account for potential endogeneity. Perceived yield is found to be the most important trait affecting farmers' adoption intention. Further, yield perceptions among previous adopters appear to be affected by within-village peer effects rather than the real crop performance. / Ph. D.

This research proposes a method for estimating the residual capacity of Li-ion batteries. The charging and discharging characteristics of Li-ion batteries are investigated and analyzed by a battery test system. The measurement of the initial capacity is based on the improved open-circuit voltage measurement, which compensates the effects of battery aging and self-discharging. The measurement of the used capacity is based on the improved coulomb counting measurement, which compensates the effects of output current and environmental temperature. The designed system provides various functions for battery charging and discharging, battery voltage measuring and recording, battery capacity estimation and calculation, and the log files can be used for further battery characteristics analysis.

The International Potato Center (CIP) and Peruvian National Agricultural Research Institute (INIA) have invested a substantial amount of resources towards the development of improved potato varieties in Peru. These varieties are adaptable to the agro-ecologies of the Andes and have specific biotic and abiotic attributes. These efforts have led to the release of several prominent varieties including Canchan-INIA, Amarilis, Unica, Serranita and others. A 2013 household survey conducted by CIP was used to describe the diffusion of improved potato varieties in Peru. These data were also used to identify specific constraints to their adoption and dis-adoption. The assessment focused on a two-step adoption model, adoption and dis-adoption, by utilizing a Heckman Probit model to demonstrate two-steps of the adoption process. The Heckman Probit model was used to analyze variables affecting adoption and dis-adoption of improved varieties. Results suggest that adoption is region specific, time dependent, and in some cases relies on informal transmission methods. Risk to food insecurity and recurrent natural phenomena affect adoption and sometimes dis-adoption. Additionally, factors affecting a farmer's exposure to risk, such as information constraints and household head age, wealth, and social network were found to affect the adoption and dis-adoption of improved varieties. / Master of Science

Faculty of Information Systems School of Economic and Business Sciences 9406128v georgia.sirinidis@fnbcorporate.co.za / Interpersonal Conflict is a neglected topic in Information System Development (ISD). While deemed important, few ISD studies have examined interpersonal conflict, the management of this conflict, or the impact this conflict has on project outcomes. Research in this field has revealed that conflict between different user groups within the systems development team is considered to be a significant threat to the success of a project. Failed systems have been attributed to resistance to system change, political issues that arise as a result of the system change and poor qua lity of teamwork between users and technical staff, analysts, programmers and other IS professionals and cultural differences. Better methods of systems analysis and design are thus needed to ensure appropriate, feasible and acceptable programs and applications and it is therefore with this intention, that this dissertation is submitted: to consider organisational behavioural means, in particular the importance of negotiating within the Systems Development process, to improve systems development. There were multiple objectives to this dissertation. These were: · to investigate whether system development is currently experienced as a process of conflict · to ascertain which roles experience a greater degree of conflict · to ascertain which systems development life cycle (SDLC) and which methodologies experience a greater degree of conflict · to assess whether negotiating skills vary across the different roles within the SDLC, to assess whether negotiating skills vary across SDLC methodologies · to determine whether the interest to improve negotiating skills varies within the SDLC · to evaluate the importance attached to negotiating skills in the SDLC · to assess whether the acceptance of the proposed negotiating framework for systems development varies within the SDLC · to examine what factors play a role in the acceptance of the proposed frameworks and · to assess whether the proposed framework will improve systems delivery. ii The reach of the research was limited to organisations in Southern Africa. These organisations were either large software development houses, or small IT departments within organisations, which specialised in developing either outsourced systems or in- house systems. Selfadministered questionnaires were mailed out to system development teams in South Africa, of varying industries and a total sample of one hundred and fifty five respondents replied. A quantitative approach was adopted to analyse the data. The results of the research show that minimal conflict is currently experienced in the SDLC and respondents across all roles and methodologies feel they possess negotiation skills to handle the conflict. The majority of the sample favourably accepted the proposed framework. Some roles attached more importance to the need for negotiating skills in their line of work, and paid more attention to improving their negotiating skills than others.

Over the past decade a large amount of research has been dedicated in academic literature to improving the technical capabilities of improved cookstoves; primarily the performance efficiency and reduction of emissions. Unfortunately, as published literature has highlighted, the trade-offs that result from placing such a concentrated emphasis on these technical objectives is that improved cookstoves lack the same level of usability as traditional cookstoves. Thus, users often return to using their traditional stoves and the potential impact of the improved cookstoves is never fully realized. In order for improved cookstoves to have greater impact, there must be better balance between the two competing design objectives of technical capabilities and usability. This research explores the challenges and benefits associated with achieving the appropriate balance, and provides guidance on how to more effectively achieve this. A list of the most common customer needs from around the world is provided for cookstoves. Interestingly, there are needs that are common to all cookstove users (global needs), and needs that apply to only a subset of users (local needs). Due to the diversity of such needs, there are many unique challenges that come with trying to satisfy these in the design process. A design methodology is presented that accounts for these challenges and helps balance the competing design objectives. This methodology is demonstrated through the modification of a traditional cookstove used in the Tambogrande region of Peru. This modification includes an inexpensive set of pot skirts that integrates directly with the traditional stove. These pot skirts allow for varying sizes and number of pots, and the use of traditional fuels. Laboratory testing, using the Water Boiling Test (WBT), identified the skirts' technical improvements: 41.7% increased thermal efficiency, 32.7% decreased fuel consumption, 28.8% decreased time to boil. Field testing was performed to determine the pot skirts' acceptance and compatibility with the traditional cookstoves, with over 75% of the participants recognizing some type of benefit. Although the technical improvements of these pot skirts are less than other cookstoves on the market, the higher levels of usability are likely to lead to a more positive end-user reaction, which could potentially lead to higher rates of adoption and impact. Though this research is primarily focused on the application of improved cookstoves, the need for more balance between technical and user objectives is applicable to nearly all products being designed for the developing world.