<p>This thesis is focused on the mechanisms for corrosion andhydriding of Zircaloy. Special attention is paid tomicrostructural characterisation by cross sectionaltransmission electron microscopy of the oxide layer formed.Three main topics have been treated in this work: (i)Pre-transition oxides were investigated with the purpose ofevaluating if it is possible to predict post-transitionbehaviour of different alloys. (ii) The reason for the commonlyobserved accelerated corrosion of Zircaloy in the presence oflithium hydroxide was investigated by studying the phasetransformation of differently stabilised zirconium oxides andby corrosion studies. (iii) Pre-hydrided Zircaloy-2 was studiedto investigate the influence of hydrogen on the oxidationbehaviour.</p><p>Characterisation of pre-transition oxides formed onzirconium alloys, has been accomplished with the aim ofdetermining if there are any differences in the properties(morphology, pores, cracks and phases) of the oxide layersformed which might explain the differences in corrosionbehaviour later in life. Four Zircaloy-2 versions and oneZircaloy-4 version were tested in an autoclave at 288° Cfor 20h and 168h and at 360˚C for 96h. Based on thecharacterisation of pre-transition oxide layers only small orno differences were found between the different alloycompositions, thus it is not possible to predict long-timecorrosion behaviour by studying pre-transition oxides. However,large differences were found between the two test temperatures.The higher oxidation temperature results in increased oxidationrates and larger oxide grains, the columnar grains are a factorof 3-4 longer, and the equiaxed grains have an almost doubledmaximum diameter. The fraction of columnar grains andtetragonal phase also increases with temperature. The reasonfor the difference in morphology between the two temperaturesis not fully understood, but the results show that acceleratedtesting at elevated temperatures may be a questionableapproach. One of the Zircaloy-2 samples was also anodicallyoxidised. The oxide layer formed only contains equiaxed grainsand phase analysis shows both monoclinic and tetragonal phasesare present.</p><p>Oxidation tests of Zircaloy-2 and Zircaloy-4 in water andlithiated water at 360 ° C show that the pre-transitionoxidation rate is not affected by the presence of LiOH, but thetransition occurs earlier and the post-transition oxidationrate is increased. The oxidation rate correlates with thedensity of cracks in the oxide layer and the morphology of theoxide grains. The oxides formed have a layered structure andfor samples oxidised in LiOH solution the inner protectivelayer is thin. The effect of LiOH is suggested to be the resultof partial dissolution of the oxide and subsequentincorporation of lithium ions during adissolution-precipitation process. Newly formed oxide isprobably more hydrous, and the grain boundaries areparticularly liable to dissolution. The increased concentrationof LiOH within cracks and pores could reach the detrimentallevels necessary for dissolution. This is supported by theinsensitivity in the pre-transition region to both thecompositions of the alloy and to the environment. The alloycomposition influences the microstructure of the oxide layer,and thereby the resistance to accelerated corrosion rate inlithiated water. The hydrogen pickup ratio follows the weightgain, not the oxidation rate, up to the second transition. Whenthe protective oxide layer is degraded the hydrogen pickupratio increases markedly.</p><p>To evaluate if hydrogen is a cause for or a consequence ofaccelerated corrosion, pre-transition oxidation tests ofZircaloy-2 have been performed with hydrogen present in threedifferent states: i) Hydrogen in solid solution in thezirconium alloy, corresponding to the initial oxidation priorto precipitation of hydrides. ii) Uniformly distributedhydrides simulating a situation in whish hydrides starts toprecipitate and iii) Massive surface hydride claimed to be themain cause of accelerated oxidation. Based on the resultsobtained, it is concluded that the oxidation of massivezirconium hydride resembles the oxidation of zirconium metal.This fact clearly shows that accelerated oxidation of zirconiumalloys cannot be due solely to the presence of a massivehydride layer, but also requires a combined effect offorexample interfacial roughness and hydride precipitation.</p><p><b>Keywords:</b>Zircaloy, Zirconium alloys, Oxidation, Oxidelayer, Pre-Transition, Hydriding, Pre-Hydrided, Hydrides,Lithium Hydroxide (LiOH), Lithiated Water, Dissolution, CrossSectional TEM</p>

Syftet med den här studien är att undersöka om utbildningens kvalitet har en signifikant påverkan på ekonomisk tillväxt. I uppsatsen tillämpas en regressionsanalys baserad på sekundärdata. Den beroende variabeln är real BNP per capita tillväxt vilken används för att mäta ekonomisk tillväxt. Den oberoende variabeln i fokus är testresultat från internationella prov och används som mått för utbildningens kvalitet. Kontrollvariabler i uppsatsen är initial BNP per capita, genomsnittlig utbildningstid, fertilitet, investeringar och graden av handelsöppenhet. I studien ingår data för 49 länder och omfattar åren från 2000 till och med 2010. I regressionsmodellen som inkluderar samtliga kontrollvariabler visar testresultatvariabeln en signifikant positiv relation till ekonomisk tillväxt. Det här betyder alltså att utbildningens kvalitet har en påverkan på ekonomisk tillväxt. Utifrån detta går det att härleda ett antal teoretiska förklarningar till hur utbildningens kvalitet har kunnat påverka ekonomisk tillväxt. I och med innovationer i informationsteknik samt den generella teknologiutvecklingen som präglat 2000-talet, dras slutsatsen att utbildningens kvalitet troligtvis har påverkat utvecklandet av färdigheter relaterade till innovationsförmåga och anpassningsbarhet till ny teknologi hos individer. Det här i följd har påverkat den ekonomiska tillväxten i ett land. / The purpose of this study is to investigate whether the quality of education has a significant impact on economic growth. This paper applied a regression analysis based on secondary data. The dependent variable is real GDP per capita growth, which is used to measure economic growth. The independent variable in focus is test results from international tests and is used as a measure of educational quality. Control variables in the paper are initial GDP per capita, average years of schooling, fertility, investments and the degree of trade openness. The study includes data for 49 countries and covers the years from 2000 to 2010. The regression model that includes all control variables shows that the test result variable has a significant positive relationship to economic growth. This means that the quality of education has an impact on economic growth. Based on this it is possible to derive a number of theoretical explanations of how the quality of education has been able to influence economic growth. With innovations in information technology, as well as the general technology trend that characterized the 2000s, it’s concluded that the quality of education is likely to have influenced the development of skills related to innovation and adaptability to new technologies in individuals. Consequently, this affects the economic growth of a country.

The primary objective of the study is to evaluate the safety performance of different freeway exit types used in current practical designs. More specific, the research objectives include the following two parts: 1) to compare the safety performance of different design types at freeway diverge areas and exit ramp sections; and 2) to identify the impact factors contributing to the crashes happening at these two specific segments. The study area includes four subjects, the freeway widely-spaced diverge areas; the freeway closely-spaced diverge areas; the left-side off-ramps and the exit ramp sections. For the freeway diverge areas, design types were defined based on the number of lanes used by vehicular traffic to exit freeways and lane-balance theory. Four exit ramp types were considered for the widely-spaced diverge area, including single-lane exit ramps (Type 1), sing-lane exit ramps without a taper (Type 2), two-lane exit ramps with an optional lane (Type 3), and two-lane exit ramps without an optional lane (Type 4). For the closely-spaced diverge areas, three types, named as Type A, Type B and Type C, are selected to compare the safety performances among the three types. For the left-side off-ramp at the freeway diverge area, this study examined the two most widely used design types at the left-side freeway diverge areas in Florida, which are defined as Type I (one-lane left-side off-ramp), and Type II (two-lane left-side off-ramp). Type I is comparable to Type 1 design type and Type II is comparable to Type 3 design type at widely-spaced freeway diverge area. For the exit ramp sections, four ramp configurations, including diamond, out connection, free-flow loop and parclo loop, were considered. Cross-sectional comparisons were conducted to compare the crash frequency, the crash rate, the crash severity and target crash types between different design groups. Crash predictive models were also built to quantify the impacts of various contributing factors. The results of this study would expectedly help transportation decision makers develop tailored technical guidelines governing the selection of the optimum design combinations at freeway diverge areas and exit ramp sections.

The Caloosahatchee River, located in Southern Florida, was originally a meandering and relatively shallow river. During the 1920s, the Caloosahatchee River was channelized and became the C-43 canal. The channelization has significantly impacted the river ecosystem, particularly the oxbows. The oxbows are the U-shaped water bodies on each side of the river channel, which are the remnant bends of the original river. To understand how anthropogenic influence affects hydrologic systems, the proposed case study was designed to assess the geomorphic changes of the oxbows of the Caloosahatchee River, Florida. Understanding and documenting the evolution of river morphology is becoming increasingly important today with increasing river degradation due to anthropogenic activities. In fact, such monitoring will provide critical information regarding river conditions to support future management plans and restoration efforts. Monitoring is a key element of successful management. This study provided a baseline for future monitoring by assessing the current morphologic conditions of the thirty-seven oxbows of the Caloosahatchee River, coupled with GPS data. Bathymetric surveys were used to assess the morphology of the oxbows. The study also presented trends in the evolution of oxbow morphology by comparing the data collected from the survey in 2011 with a cross-sectional survey collected by the South Florida Water Management District in 1978. The study revealed that 21 of 37 oxbows are still open; however, 16 are already partially filled, either at one of the ends or somewhere in the interior. In both 1978 and 2011, oxbows in Lee County were significantly larger, wider and deeper than in Hendry County. Exterior limb cross-sections were significantly larger, wider and deeper than interior cross-sections in both 1978 and 2011. Finally, an attempt to determine trends in the evolution of the morphology of the oxbows demonstrated that the overall maximum depth is significantly decreasing but only in the interior of the oxbow and that the mean depth is significantly increasing but only in the exterior cross-sections. This analysis also showed that the width is significantly increasing throughout the oxbow. Factors responsible for such differences may include natural geomorphic processes, pattern changes due to channelization, land use and anthropogenic activities.

The goal of this study was to explore technology experiences from a preservice teacher preparation program that requires every preservice teachers and instructors to own a laptop. The participants were a) preservice teachers who were in the program and b) novice teachers who are the program graduates. The setting of this study was a preservice teacher preparation program that involves one-to-one computing throughout in a college of education in a large southwestern university. The research conducted a cross sectional case study. Two preservice teachers across the first, second, and third semesters of the program and two novice teachers in the first year of teaching participated in this research. Various data sources were collected with: a) technological skills and attitude survey, b) related documents such as lesson plans, assignments and school documents, c) observation, and d) interviews. Results of this study showed each participant’s learning environment, technology experiences and technology skills, attitudes and knowledge. All preservice teachers mutually had media cart, instructors’ laptops, students’ laptops, and wireless internet in university classes, and had innovation station, teachers’ computers, printer, telephone, students’ computers, headsets and wireless internet in PK-6 school classes. Throughout the program, university instructors mutually required Email, word processing and electronic submission of assignments to the preservice teachers. The instructors mutually modeled using PowerPoint and Learning Management System (LMS). Preservice teachers in the first semester mutually used video creation, preservice teachers in the second semester used Email and LMS, and preservice teachers in the third semester mutually used search engine, PowerPoint and innovation station. All participants’ technology attitudes were overall positive. Most of the preservice teachers’ technology knowledge was rated accepting level, except Neal, one of the preservice teachers in the third semester, who was rated adapting level. Novice teachers mutually had innovation station, web conferencing devices and students’ laptops in their school. Both of the novice teachers experienced barrier of technology integration due to the necessary devices were already checked out. The novice teachers mutually used innovation station, had overall positive technology attitudes and had technology knowledge at the accepting level. The results led six discussion issues, including a) alignment of technological infrastructure, b) accessibility of technologies, c) limited exposure to technological activities, d) preservice teachers’ technology skills, e) technology experiences from the program and preservice teachers’ technology attitudes, and f) programmatic impact on novice teachers. / text

Innovative ways to conduct disease surveillance are required to address the complexity of Ciguatera Fish Poisoning (CFP). Mixed methods were employed to explore CFP epidemiology and interdisciplinary approaches to its surveillance in the Turks and Caicos Islands (TCI). Quantitative analyses of cross-sectional data collected by the TCI’s National Epidemiology and Research Unit in 2010 demonstrated that a low percentage of residents reported lifetime histories of illness following fish consumption (3.9%). Furthermore, gender, age, island, and home remedy use were significantly associated with reported clinic visitation by ill individuals. Next, a multisectoral CFP surveillance model was conceptualized. A qualitative exploration of the model’s hypothetical integration into TCI’s health system revealed that several systemic and contextual factors could influence the future uptake of interdisciplinary CFP surveillance. Targeted interventions are recommended to improve national CFP surveillance and to facilitate the growth of interdisciplinary networks between stakeholders from TCI’s health, fisheries and environment sectors. / Canadian Institutes of Health Research, Ontario Veterinary College, University of Guelph, Ministry of Health and Human Resources of the Turks and Caicos

<p><font face="Times New Roman" size="3"><font face="Times New Roman" size="3"> <p align="left">The study made use of cross-sectional design that compared the performance of younger children (6- to 7-year-olds) with that of older children (12- to 13-year-olds) on various measures of executive function. Within this, it made use of a natural experimental design, with children exposed to alcohol<i><font face="Times New Roman" size="3"> as the experimental group and non-exposed children as the control group.</font></i></p> </font></font></p>

The study investigated three aspects related to smoking, namely, smoking behaviour, risk perception and attitudes to anti-smoking legislation. The theoretical framework of the study was the Information-Motivation-Behavioural (IMB) skills model. The study was a quantitative one, making use of a cross-sectional survey design to obtain data about the three variables of interest. Responses to statements about risk perception and attitudes to anti-smoking legislation in the questionnaire were arranged on a three-point Likert scale. The inferential statistics used were one-sample ttests and Chi-square analyses. The results showed an overall smoking prevalence of 16%, with twice as many females than males being smokers in the sample. ‘Coloured’ students in both genders had the highest smoking rate compared to all other race groups. The knowledge of the health risks of smoking were very high, however smokers had a lower perception of risk compared to non-smokers. Moreover, while there was a fair amount of support for anti-smoking legislation among smokers, smokers tended to show less support for legislation than non-smokers, especially to those parts of the legislation that affect them more directly. The results of the study indicate a clear connection between smoking behaviour and the effect it has on both risk perception as well as attitudes to anti-smoking legislation in individuals.

<p>Low back pain (LBP) is a significant problem among the nursing population worldwide. Manual lifting and shifting of heavy objects and patients are primary contributing factors. Nurses are supposed to be knowledgeable about the risk factors and preventive measures and effectively apply it into practice to prevent them from sustaining back injuries. Strategies to reducing the incidences of LBP in nurses have been previously implemented but with little outcomes. The purpose of this study was to explore the relationship between occupational risk factors and the prevalence of LBP in nurses at MOI, Tanzania. Therefore, the study examined / the prevalence of LBP amongst nurses, work-related risk factors contributing to LBP, knowledge and effectiveness of back care techniques, and barriers to effective back care techniques in clinical nurses.</p>

AIM: The overall aim of this thesis was to examine the associations between dental anxiety, experiences of dental care, psychosocial factors and oral health among 15-year-olds, and to analyse changes in the prevalence of dental anxiety over time. MATERIALS AND METHODS: The thesis was based on two cross-sectional epidemiological studies in Jönköping, Sweden. Papers I, II, and III were based on a random sample of 15-year-old individuals. The total sample consisted of 221 individuals. Six questionnaires were used, one included items of background data, while the others were psychometric instruments measuring dental anxiety, temperament, general anxiety and depression, general fearfulness and attitudes to dental care. Paper IV was based on the Jönköping studies, a series of epidemiological studies from 1973, 1983, 1993, and 2003 in which random samples of 15-year-old individuals were included. The total sample consisted of 405 individuals. Questionnaires including background data and dental anxiety were used and clinical data were collected. RESULTS: Of the 15-year-old individuals 6.5% were classified as dentally anxious with girls proportionally more fearful than boys (Papers I-III). Dental anxiety correlated significantly with three of the temperament dimensions; emotionality, activity and impulsivity. Reported pain or unpleasant experiences during dental care treatment were clear predictors concerning dental anxiety (Paper I). Both symptoms of general anxiety and depression were significantly correlated with dental anxiety after controlling for other potential risk factors (Paper II). Dental anxiety was associated with both general fearfulness and with attitudes to dental care, where the strongest predictor of dental anxiety was general fearfulness (Paper III). A trend analysis over the 30-year period showed a gradient of statistically significantly decreasing dental anxiety prevalence, from 38.1% in 1973 to 12.8% in 2003. Over the period the 15-year-old individuals with dental anxiety had significantly higher number of filled tooth-surfaces than those with no dental anxiety, and also more caries in 1973. There were no such differences concerning plaque and gingivitis (Paper IV). CONCLUSIONS: Dental anxiety in 15-year-olds correlated with experiences of dental care, psychosocial factors as well as to oral health. Specifically, pain experiences related to dental care, attitudes to dental care and general fearfulness seem to have the strongest impact on dental anxiety. Dental anxiety showed a clear declining change over time. More girls than boys reported dental anxiety. The thesis shows that dental care providers need paying attention on providing a supportive dental care situation, in which the patients should not experience pain. One part may be adequate local anaesthesia during operative dentistry or similar dental treatments. Another part may be a good oral health to prevent negative experiences of dental care. There is a need for the understanding of psychological factors associated with dental care procedures. / SYFTE: Det övergripande syftet med denna avhandling var att bland 15-åringar undersöka sambanden mellan tandvårdsrädsla, erfarenheter av tandvård, psykosociala faktorer och oral hälsa, samt att analysera förändringar i förekomsten av tandvårdsrädsla över tid. MATERIAL OCH METOD: Avhandlingen baseraspå två epidemiologiska tvärsnittsstudier i Jönköping. I arbete I, II och III redovisas studier av 221 slumpmässigt utvalda 15-åriga individer. Deltagarna besvarade frågor avseende bakgrundsdata, tandvårdsrädsla, temperament, ångest och depression, generell rädsla samt attityder till tandvård. Arbete IV bygger på Jönköpingsstudierna, från 1973, 1983, 1993, och 2003, där sammanlagt 405 slumpmässigt utvalda 15-åriga individer ingick. Datainsamling gjordes med hjälp av frågeformulär, bestående av bakgrundsdata och tandvårdsrädsla, samt kliniska data. RESULTAT: Resultatet i arbete I, II och III visade att 6,5% av ungdomarna rapporterade hög tandvårdsrädsla, där en övervägande andel var flickor. I arbete I visade tandvårdsrädsla samband med tre av temperamenten; emotionalitet, aktivitet och impulsivitet. Rapporterad smärta eller obehagliga upplevelser under tandbehandling var tydliga prediktorer avseende tandvårdsrädsla. I arbete II visade både symtom på ångest och depression samband med tandvårdsrädsla, sedan effekterna av andra potentiella riskfaktorer hade kontrollerats för statistiskt. I arbete III visade tandvårdsrädsla starkt samband med både generell rädsla och med attityder till tandvård, där den starkaste prediktorn för tandvårdsrädsla var generell rädsla. I arbete IV visade en trendanalys en statistiskt säkerställd minskning gällande förekomsten av tandvårdsrädsla, från 38,1% år 1973 till 12,8% år 2003. Ungdomarna med tandvårdsrädsla hade signifikant fler fyllda tandytor än ungdomarna utan tandvårdsrädsla under 30-årsperioden, och år 1973 även mer karies. Det fanns inga sådana skillnader avseende plack och gingivit. SLUTSATSER: Resultatet visar att tandvårdsrädsla är relaterat till smärtsamma erfarenheter av tandvård, generell rädsla, och oral hälsa. Resultatet visar också att tandvårdsrädsla hos 15-åringar har minskat över tid och är vanligare hos flickor. Resultaten pekar på att tandvårdspersonalen har en viktig uppgift i att unga tandvårdspatienter inte utsätts för smärtsam behandling. Framtida forskning av intresse kan vara hur olika sätt att administrera lokalbedövning kan förändra uppfattningen av smärta och nivåer av tandvårdsrädsla.