Les activités industrielles de traitement des minerais sont à l’origine d’importantes quantités de rejets minéraux dans l’environnement. Ceux-ci ont un impact direct sur l’environnement et la santé. La caractérisation de ces rejets constitue donc un enjeu majeur en termes de suivi de la qualité des sols et des eaux. La télédétection hyperspectrale fait partie des outils qui peuvent contribuer à l’identification, à la localisation et à la cartographie à distance des minéraux marqueurs des contaminants. Ce travail a porté sur l’étude de deux sites industriels, à Thann (Haut-Rhin, France) et à Gardanne (Bouches-du-Rhône, France), à plusieurs échelles afin d’établir le lien entre la minéralogie identifiée par des analyses minéralogiques et géochimiques et les signatures spectrales. Les signatures spectrales sont mesurées par le biais de spectromètres en laboratoire et sur le terrain et par le biais des capteurs aéroportés hyperspectraux APEX et HySpex. Une méthode de déconvolution spectrale a été développée dans le but d’identifier automatiquement les minéraux. Cette méthode a été évaluée sur des spectres synthétiques et des spectres de minéraux purs. Elle a ensuite été appliquée sur les matériaux présents sur les deux sites industriels étudiés confirmant ainsi le potentiel des données hyperspectrales pour la caractérisation des minéraux industriels. / Industrial activities related to ore processing can release large amounts of mineral waste in the environment. Such waste can contain hazardous materials and have a direct impact on the environment and on health. Characterizing those waste allows to assess the quality of soils and waters. Hyperspectral remote sensing is one of the available tools to identify, locate, and map these minerals. This work focuses on the study of two industrial sites, in Thann (Haut-Rhin, France) and in Gardanne (Bouches-du-Rhônes, France), at different scales in order to assess the link between the mineralogy inferred from mineralogical and geochemical analyses and the spectral signatures. Spectral signatures are measured by spectrometers in the laboratory and in the field and by the APEX and HySpex airborne hyperspectral sensors. A déconvolution method has been developed to automatically identify the minerals. This method has been evaluated on synthetic spectra and pure minerals spectra. It has been then applied to the waste of the industrial sites under study, thus confirming the potential of hyperspectral data for the characterization of industrial minerals.

Thesis (M.Sc.)--Boston University, Henry M. Goldman School of Graduate Dentistry, 1992 (Dental Public Health). / Includes bibliographical references: (leaves 37-39). / Changes in the external environment and the dental needs of the public have placed greater demands on dental schools to graduate dentists better prepared to enter dental practice. New disease patterns, an aging population, and technological advancements, as well as, rising tuition and a decline in the applicant pool, are factors which are forcing dental educators to re-evaluate the curriculum and create new methods in which dentistry can be taught. One such method, experiential learning, has been a major component in professional education for many years. Law schools and medical schools have utilized the court system and hospitals respectively to train students to function in a professional environment. Only on a limited basis have dental schools embraced off-campus facilities to assist them in their training. In 1989, Boston University’s Goldman School of Graduate Dentistry responded to this need for change by restructuring its pre-doctoral curriculum. The restructured curriculum introduced new approaches to science, technology, and healthcare management. One very important addition to the pre-doctoral curriculum is the Applied Professional Experience Program (APEX.) The APEX Program, the first of its kind in dental education, allows students to alternate between the classroom and clinical studies, and dental clerkships in Boston area dental practices. The APEX Program enables dental students to function as dental interns while receiving paid professional work experience. It is hoped that the APEX experience will produce a more well-rounded graduate, who has had the opportunity to function in a professional dental environment throughout his or her education. Experiential learning, the educational concept for APEX, develops a strong link between dental education and the actual delivery of health care services. APEX benefits all who are involved with the program: the student, the school, the dentist, and the dental community. Since its beginning the program has been continuously monitored through an on-going evaluation process to ensure that the program’s goals and objectives are being met. On average, 50 dental offices have been required to meet the needs of the program. As dental offices have withdrawn from the program, new offices have been recruited to replace them. To date, a total of 14 dental offices have withdrawn from the program. As part of the on-going program evaluation process, this project will describe and compare the similarities and differences of the dental offices which are currently participating in the APEX Program with those dental offices which have withdrawn from the program. It will also be comparing the similarities and differences of the attitudes of the dentists regarding APEX, student involvement, and perceived benefits for the dentist, the dentist’s staff, and the APEX intern.

The aim of this research is to assess hazards and risks associated with flooding in the city of Juárez, northern México, where there is a flood threat from active alluvial fans from mountains to the southwest and from the Rio Grande (Bravo River) to the northwest forming the northeast border of the city. Aims of this Ph.D. were addressed processing a digital elevation model (DEM) of the study area in a GIS platform to define the several alluvial fans, and thus to examine their history and palaeohydrology. Three OSL dates in the youngest parts of the fans show ages ranging from 74 - 31 ka. However, the fans were subsequently incised, broadly correlating with later Pleistocene to Holocene processes upstream, published in literature, in New México. These changes are not obviously linked to glacial-interglacial cycles, and there is indication of local controls of interplay of climate and topography, for which this work is a preliminary study. The flood threat to Juárez was addressed by using a classification of the uneven topography of the eroded alluvial fans, plus the Bravo River flood plain, into basins and subbasins. Field and laboratory work was used to define litho-facies of soils and rocks, location of structures such as, topographic and hydrologic apex and drainage system in the fans. The data were then used in association with published information on the parameters of the basins and sub-basins provided in published documents from the Mexican authorities to make flood models of the area, using standard models of HEC-HMS and HEC-RAS methods widely applied in semi-arid regions. The result was estimation of the ability of existing flood defences to resist high-flow floods that may be expected in upcoming decades. The modelling predicts that only a small number of the existing defences will hold in a catastrophic 1:100-year flood, and that substantial parts of the city are in considerable danger. Such results are important in relation to the expanded and dense population in Juárez, which is concentrated mostly on the most active part of the flooding system, the Colorado Fan, which is the subject of a focussed secondary study of vulnerability mapping. The map reveals that areas of the city of low socioeconomic development are under the greatest threat. Therefore there is a need for reconsideration of the city's flood planning, and remediation, plus the application of enforcements of areas which should not be built on, because of the threats.

Sensitivity analysis is essential for the hydrologic models to help gain insight into model’s behavior, and assess the model structure and conceptualization. Parameter estimation in the distributed hydrologic models is difficult due to the high-dimensional parameter spaces. Sensitivity analysis identified the influential and non-influential parameters in the modeling process, thus it will benefit the calibration process. This study identified, applied and evaluated two sensitivity analysis methods for the APEX model. The screening methods, the Morris method, and LH-OAT method, were implemented in the experimental site in North Carolina for modeling runoff, sediment loss, TP and DP losses. At the beginning of the application, the run number evaluation was conducted for the Morris method. The result suggested that 2760 runs were sufficient for 45 input parameters to get reliable sensitivity result. Sensitivity result for the five management scenarios in the study site indicated that the Morris method and LH-OAT method provided similar results on the sensitivity of the input parameters, except the difference on the importance of PARM2, PARM8, PARM12, PARM15, PARM20, PARM49, PARM76, PARM81, PARM84, and PARM85. The results for the five management scenarios indicated the very influential parameters were consistent in most cases, such as PARM23, PARM34, and PARM84. The “sensitive” parameters had good overlaps between different scenarios. In addition, little variation was observed in the importance of the sensitive parameters in the different scenarios, such as PARM26. The optimization process with the most influential parameters from sensitivity analysis showed great improvement on the APEX modeling performance in all scenarios by the objective functions, PI1, NSE, and GLUE.

Tillage practices on agricultural fields have an impact on not only the amount of soil erosion from the fields, but also on the hydrologic and other environmental characteristics of the land. This erosion takes away soil that is necessary for sustainable agriculture, and the sediment and nutrient removal from the fields can pollute surrounding waterbodies. The Llanos Orientales of Colombia used to be a region of extended savannas and native fragile ecosystems dedicated to extended cattle ranch that has been transitioning to crop production. Agricultural expansion in this area, involving mechanization, could importantly accelerate the degradation of soils, limiting the development of sustainable agricultural systems. As a first step to understand long term effects of different tillage practices on new agricultural areas in the region, this study aims to evaluate the performance of the Agricultural Policy Environmental eXtender (APEX) model to simulate runoff, soil erosion and crop yield from fields under conventional tillage, reduced tillage, and no tillage in the Llanos Orientales of Colombia. Calibrated APEX model predictions were compared against measured runoff, soil loss and crop yield data from row crop plots established in the Experimental Station la Libertad in Colombia under conventional, reduced and no-tillage management. APEX satisfactorily predicted runoff (Nash Sutcliffe Efficiency NSE>0.53, Percent Bias - [PBIAS] < 21%) and crop yield for all three tillage systems (NSE>0.82, [PBIAS] <15%), but was not successful in predicting soil loss from the studied plots. Unsuccessful results were related to model limitations to predict erosion (USLE equations), but also to any uncertainty attributed to issues in the data collection. A calibrated APEX model could be used to predict runoff and crop yield responses under different management practices in the Llanos Orientales of Colombia, but needs improvements for prediction of soil erosion in tropical soils.

The purpose of this in-vitro study is to compare the accuracy and reliability of a 3rd and 4th generation electronic apex locator (EAL) in locating the apical foramen when using insulated and non-insulated K files. Forty extracted human adult single-rooted teeth were coronally sectioned and placed in agar. EAL determined tooth length measurements were compared to actual tooth measurements. Comparisons to the standard measures used correlation and paired t-test. Preliminary comparisons of the groups used ANOVA to compare the means and the Brown-Forsythe test to compare variance. In the final analyses, the measurements were compared using a repeated-measures mixed-model multiway ANOVA that allowed for heterogeneous variance in the subgroups. Findings were that accuracy is not different due to insulation in the Root ZX group (p-value=0.50) but is improved in the Elements Diagnostic Unit group (p-value<.001). Reliability is nominally improved with insulation in both the Root ZX and Elements Diagnostic Unit.

No description available.

The master’s thesis deals with analysis of sealing elements of Wankel engines and their design. The necessary steps for creation of the model of dynamics of apex seal are provided, whereby the resulting force loads are then obtained. Furthermore, the design of the apex seal spring, the choice of the material and the production jigs for the production of the spring itself are presented. The finished components are tested in the engine testing laboratory and the results evaluated.

Purpose: This thesis aims to explore the complex phenomenon of leadership at the apex of democratically elected local authority in England. It makes sense of the social construction of leadership as perceived and enacted by senior appointed officers (hereinafter officers), elected members (hereinafter members) and key stakeholders – the voices from the apex and their understandings and interpretations. Design/methodology/approach: The thesis examines leadership literature through the paradigm of constructivism-interpretivism, making sense of transcripts of the semi-structured interviews with officers, members and stakeholders engaged in local authority work. Dominant/mainstream theories of leadership offer limited help to understanding the relational, processual constructions of leadership and is critiqued. One way forward is to rethink conceptualisation of leadership in terms of the empirical evidence through interviews. This research has explored how leadership is situated, shared and occasioned, processed and deployed as narratives between officers and members. Findings: The constructivist-interpretivist findings of the research challenges the dominant essentialist hegemony of existing leadership theories, where heroic leaders and their skills and competencies can be replaced by less individualistic and more critical constructs through the four lenses which draw together in the fractal of leadership. This moving, forming and reforming, dynamic model highlights: i) the context in which leadership is situated and performs, ii) the shared and relational nature of leadership in interactions and continuous happenings, and the web of roles and relationships between powerful actors, which are perpetually evolving and contextualising, iii) the doing of leadership with its focus on interactive processes and practices, and iv) the narratives of leadership including the language games, the rhetoric, the metaphors and symbols which can challenge as well as reinforce the existing patterns of leadership as they emerge and mould and are moulded in diverse patterns. Research limitations/implications: Though the findings themselves cannot always be generalised to other contexts, the four frames of the fractal provide theoretical perspectives for studying leadership in other contexts. Originality/value: By challenging the dominating mainstream and public leadership theories, the four theme leadership framework allows for the incorporation of dynamic lenses to study the complex social phenomena of leadership. The analogy with a kaleidoscopic fractal enables a rich understanding of leadership rooted in a specific context yet with endless possibilities of leadership built from the permutations and combinations of the four themes. This thesis makes a theoretical and empirical contribution to the questions of the how, why and what of organisational leadership, both in a broad sense and in the specific context of the public sector and local authority in particular.

Doctor of Philosophy / Agronomy / Nathan O. Nelson / Agricultural fields contribute phosphorus (P) to water bodies, which can degrade water quality. The P index (PI) is a tool to assess the risk of P-loss from agricultural fields. However, due to limited measured data, P indices have not been rigorously evaluated. The Agricultural Policy/Environmental Extender (APEX) model could be used to generate P-loss datasets for P index evaluation and revision. The objectives of the study were to i) determine effects of APEX calibration practices on P-loss estimates from diverse management systems, ii) determine fertilizer and poultry litter management effects on P-loss, iii) evaluate and update the Kansas PI using P-loss simulated by APEX and iv) determine appropriate adsorption isotherms with advection-dispersion equation with column leaching experiment. Runoff data from field studies in Franklin and Crawford counties were used to calibrate and validate APEX. Poultry litter and inorganic fertilizer application timing, rate, method, and soil test P concentration effects on P loss were analyzed using location-specific models. A column leaching laboratory study was also conducted to test the adsorption isotherms. Location-specific model satisfactorily simulated runoff, total P (TP) and dissolved P (DP) loss meeting minimum model performance criteria for 2/3 of the tests whereas management-specific models only met the criteria in 1/3 of the tests. Applying manure or fertilizer during late fall resulted in relatively lower TP loss compared to spring applications before planting. The Kansas-PI rating and the APEX simulated P-loss were correlated with r² of 0.40 (p<0.001). Adjusting the weighting factors for Prate, soil test P, and erosion improved the correlation (r² = 0.46; p<0.001. Using a component PI structure and determining the weighting factors by multiple linear regression substantially improved the correlation between the PI and TP loss (r² = 0.69; p<0.001). In the P-leaching experiment, both the linear and nonlinear adsorption isotherms did not fit the experimental data. A multi-reactional advection-dispersion model that better describes all the P processes and complexities in soils should be included in the future. These procedures can provide a roadmap for others interested P transport in soils and using computer models in evaluation, and modifying their PI.