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Dissertations / Theses on the topic 'Extractions'
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O'Shaughnessy, Kevin Koroluk Lorne. "Serial extractions versus late premolar extractions." Chapel Hill, N.C. : University of North Carolina at Chapel Hill, 2007. http://dc.lib.unc.edu/u?/etd,950.
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Thesis (M.S.)--University of North Carolina at Chapel Hill, 2007.<br>Title from electronic title page (viewed Dec. 18, 2007). "... in partial fulfillment of the requirements for the degree of Master of Science in the School of Dentistry (Orthodontics)." Discipline: Orthodontics; Department/School: Dentistry.
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Goulet, Clément. "Signal extractions with applications in finance." Thesis, Paris 1, 2017. http://www.theses.fr/2017PA01E066.
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Le sujet principal de cette thèse est de proposer de nouvelles méthodes d'extractions de signaux avec applications en finance. Par signaux, nous entendons soit un signal sur lequel repose une stratégie d'investissement; soit un signal perturbé par un bruit, que nous souhaitons retrouver. Ainsi, la première partie de la thèse étudie la contagion en volatilité historique autours des annonces de résultats des entreprises du Nasdaq. Nous trouvons qu'autours de l'annonce, l'entreprise reportant ses résultats, génère une contagion persistante en volatilité à l’encontre des entreprises appartenant au même secteur. Par ailleurs, nous trouvons que la contagion en volatilité varie, selon le type de nouvelles reportées, l'effet de surprise, ou encore par le sentiment de marché à l'égard de l'annonceur. La deuxième partie de cette thèse adapte des techniques de dé-bruitage venant de l'imagerie, à des formes de bruits présentent en finance. Ainsi, un premier article, co-écrit avec Matthieu Garcin, propose une technique de dé-bruitage innovante, permettant de retrouver un signal perturbé par un bruit à variance non-constante. Cet algorithme est appliqué en finance à la modélisation de la volatilité. Un second travail s'intéresse au dé-bruitage d'un signal perturbé par un bruit asymétrique et leptokurtique. En effet, nous adaptons un modèle de Maximum A Posteriori, couramment employé en imagerie, à des bruits suivant des lois de probabilité de Student, Gaussienne asymétrique et Student asymétrique. Cet algorithme est appliqué au dé-bruitage de prix d'actions haute-fréquences. L'objectif étant d'appliquer un algorithme de reconnaissance de formes sur les extrema locaux du signal dé-bruité<br>The main objective of this PhD dissertation is to set up new signal extraction techniques with applications in Finance. In our setting, a signal is defined in two ways. In the framework of investement strategies, a signal is a function which generates buy/sell orders. In denoising theory, a signal, is a function disrupted by some noise, that we want to recover. A first part of this PhD studies historical volatility spillovers around corporate earning announcements. Notably, we study whether a move by one point in the announcer historical volatility in time t will generate a move by beta percents in time t+1. We find evidences of volatility spillovers and we study their intensity across variables such as : the announcement outcome, the surprise effect, the announcer capitalization, the market sentiment regarding the announcer, and other variables. We illustrate our finding by a volatility arbitrage strategy. The second part of the dissertation adapts denoising techniques coming from imagery : wavelets and total variation methods, to forms of noise observed in finance. A first paper proposes an denoising algorithm for a signal disrupted by a noise with a spatially varying standard-deviation. A financial application to volatility modelling is proposed. A second paper adapts the Bayesian representation of the Rudin, Osher and Fatemi approach to asymmetric and leptokurtic noises. A financial application is proposed to the denoising of intra-day stock prices in order to implement a pattern recognition trading strategy
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Badenoch-Jones, Emma K. "Consent for third molar tooth extractions." Thesis, Queensland University of Technology, 2018. https://eprints.qut.edu.au/123066/1/Emma_Badenoch-Jones_Thesis.pdf.
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This project is an important contribution to the field of medico-legal practice in surgery. The thesis provides perspectives in deficient areas of objective evidence on consent for third molar tooth extractions through defined patient and judicial disclosures and understanding. The outcome of the project is an evidence-based consent form for third molar tooth extractions that will enhance the standard of patient information disclosure for this procedure by general dentists and oral and maxillofacial surgeons. The methodological process adopted is also one that can be replicated in other medical fields to yield objective evidence to guide the process of consent for any medical procedure.
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Carragher, Alison Margaret C. "The use of partial extractions for exploration /." Title page, contents and abstract only, 1999. http://web4.library.adelaide.edu.au/theses/09SB/09sbc3128.pdf.
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Robles, de la Terre Raul Rene. "Modelling continuous solid/liquid countercurrent food extractions." Thesis, University of Reading, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.363805.
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Saad, Elhusain Salem. "Defocus Blur-Invariant Scale-Space Feature Extractions." University of Dayton / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1418907974.
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Troulis, Maria J. "Dental extractions in patients receiving oral anticoagulant therapy." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/MQ37316.pdf.
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Feely, Cassandra Lynn. "Study of Methods for DNA Extractions from Feathers." Thesis, The University of Arizona, 2013. http://hdl.handle.net/10150/297561.
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Feathers have been used as a source of DNA for two decades. Feathers are made of keratinized cells which can make obtaining DNA from them difficult. This study compared three established methods of extracting DNA from feathers to ascertain if any produced a greater quantity of DNA. Each of the methods were conducted at five different time intervals (n=45). Each was a modification of the Qiagen DNeasy DNA extraction kit. A two way ANOVA determined if there was any differences among times or methods, and showed a significance difference among methods (F= 45.67, P < 0.001) but not times. A box-and-whisker plot was used to ascertain the most effective method. A second experiment employed the superior method to see if a trend of increasing DNA concentration with increasing time, suggested by first experiment's data, was real. This experiment was powered up to assure sufficient ability to detect differences among 3 sample sets if they existed (n=45). These results came back with no significance. This research found the extraction method used in Dr. Lisette Wait’s laboratory superior and has resulted in a protocol change for all extractions done in Dr. Melanie Culver's ancient DNA laboratory at the University of Arizona.
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Bottone, Anna. "Analyzing microplastics in soils : Evaluating canola oil extractions." Thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-165179.
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Small fragments of artificial polymers (microplastics, MPs) has been reported for multiple environmental matrices from our planet. The omnipresent existence of these microplastics even in remote polar areas have raised concern about their potential environmental impacts and created a need for effective and standardized analytical methods targeting their detection in environmental samples. So far, no methods have been developed for detecting microplastics in organic-rich soils. In this master thesis, I evaluate two analytical methods (both based on canola oil extractions) targeting microplastics in two contrasting soil matrices; one mineral rich (sandy mineral soil from a Podzol) and the other by organic matter (sample from a Histosol). I hypothesize that the detection of microplastic has a bias that depends on specific plastic particle properties (size, polymer type and morphology) as well as on the organic content of soil samples. My results show that the recovery of added plastics is strongly dependent on particle size and diminishes with decreasing microplastics length. This result was repeated by both extraction approaches. Polymer shape and soil characteristics (organic matter content) affect MPs recovery if oil extractions are conducted without pre-treatment (oxidation) step. Here, fibers proved most difficult to detect and low recoveries suggested that the method was not applicable to organic rich samples. The addition of a pretreatment step including oxidation with sodium hypochlorite improved recoveries for organic rich samples and removed the effect of soil type and polymer shape. Hence, the use of a pretreatment is essential to extract MPs from organic-rich soils, but it also decreases the overall recovery for all type of studied polymers and mostly fibers. My study suggests that there is a substantial bias when detecting MPs in soils that is causing a general underestimation, especially for small, fibrous particles in organic rich soils.
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Minh, Tuan Pham, Tomohiro Yoshikawa, Takeshi Furuhashi, and Kaita Tachibana. "Robust feature extractions from geometric data using geometric algebra." IEEE, 2009. http://hdl.handle.net/2237/13896.
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Castell, Oliver Kieran. "Microfluidic devices for continuous liquid-liquid-solid chemical extractions." Thesis, Cardiff University, 2008. http://orca.cf.ac.uk/54511/.
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In this study the unique properties of microfluidic flow have been exploited to generate efficient mass-transfer in continuous segmented flow to investigate an alternative approach for performing chemical extractions. The concept of extraction-enhancement, by incorporation of a solid absorbent in the extracting phase, was explored. Proof-of-principle studies focused on the use of molecularly imprinted polymers (MIPs) to increase the effectiveness of conventional approaches. Laser machining and micro-milling were used to prepare PTFE microfluidic separation devices. Importantly, this included the design and integration of a continuous-flow microfluidic liquid phase separator. Propranolol selective molecularly imprinted polymer microspheres (3.6 µm) were prepared by precipitation polymerisation. MIP performance was assessed using conventional (equilibrium batch rebinding) and segmented-flow liquid-liquid systems. Interfacial mass transfer processes that occur during segmented flow were characterised with respect to flow variables, fluid properties and channel geometries. Segment aspect ratio and flow velocity, together with channel diameter and curvature, were shown to be important. The MIP was shown to possess high affinity and selectivity for the template (propranolol). Incorporation of the MIP into a segmented flow extraction regime was shown to significantly enhance the extent of analyte extraction. Mathematical optimisation approaches showed good correlation with experimental data. On-chip phase separation was demonstrated to be 100% efficient for particle-containing and particle-free immiscible flows. The discovery of soluble MIP species possessing similar binding characteristics to their insoluble counterparts may further improve the kinetics of the reported solid-liquid-liquid extractions. It was successfully demonstrated that a solid phase material can be incorporated into an organic phase to enhance extraction from an aqueous sample either in continuous segmented flow or under equilibrium conditions. The integration of the segmented flow approach with an on-chip liquid phase separator provides a novel platform for the development of unique and highly-efficient continuous flow devices for molecular enrichments, separations and manipulations.
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Carson, Pauline. "Paediatric sedation and general anaesthetic services : choices for the future." Thesis, Queen's University Belfast, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.268224.
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Zhang, Shaomin. "Thematic knowledge extraction." Thesis, Nottingham Trent University, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.272437.
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Li, Qi. "Experimental and numerical investigations of ionic liquid-aqueous microchannel extractions." Thesis, University College London (University of London), 2018. http://discovery.ucl.ac.uk/10054094/.
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The thesis presents investigations on the process intensification behaviour in small scale separators operating in plug (segmented) flow. The continuous extraction behaviour, as well as the hydrodynamic characteristics of the liquid-liquid flow in microchannels is numerically and experimentally studied. The interphase mass transfer process using the extractant species Europium (III) as tracer was observed and quantified. The Eu(III) microfluidic extraction from nitric acid solutions was carried out in 0.2 mm and 0.5 mm channels using an ionic liquid solution (0.2M n-octyl(phenyl)-N,Ndiisobutylcarbamoylmethyphosphine oxide (CMPO) -1.2M Tributylphosphate) (TBP)/1-butyl- 3-methylimidazolium bis[(trifluoromethyl)sulfonyl]amide; ([C4min][NTf2]) as the extraction phase. Distribution and mass transfer coefficients were found to have maximum values at nitric acid concentration of 1M. Mass transfer coefficients were higher in the small channel, where recirculation within the plugs and interfacial area are large, compared to the large channel for the same mixture velocities and phase flow rates. Within the same channel, mass transfer coefficients decreased with increasing residence time indicating that significant mass transfer takes place at the channel inlet where the two phases come into contact. The experimental results were compared with previous correlations on mass transfer coefficients in plug flows. To better characterize the microfluidic flow, bright field Micro-Particle Image Velocimetry and high speed imaging were employed to measure velocity profiles and to obtain the geometric characterstics of the plug flow for the 1M HNO3 solution that was used in the extraction experiments. Correlations regarding film thickness, plug velocity and plug length are developed based dimensionless parameters. It was found that the liquid film surrounding the plug is largely affected by the changes in the front cap for the range of Capillary numbers studied (0.0224< Ca <0.299), while the droplet volume is highly dependent on the channel diameter as well as the mixture velocity. The volume-of-fluid (VOF) method is then used to model the velocities and pressure distribution in the plug flow in the channel and shows good agreement with experimental results and previous models. These features will help in optimizing the microfluidic plug flow for mixing, as well as mass and heat mass transfer enhancement. The mass transfer profiles of the extractant species Eu(III) are also studied using Laser Induced Fluorescence. Recirculation patterns appear in the dispersed aqueous phase from the plug formation stage, and 30-50 % of the mass transfer occurs during plug formation, where new interfaces are formed and mixing is enhanced from the recirculation pattern, especially at high Umix. After experiencing convection and normal diffusion extraction equilibrium achieved, the fluorescent signal in the ionic liquid phase is very strong as Eu(III) transfers into it. The correlations proposed on the hydrodynamics and observations of the mass transfer characteristics during plug flow will contribute to the development of microfluidic devices.
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Ducat, Thomas. "Mori extractions from singular curves in a smooth 3-fold." Thesis, University of Warwick, 2015. http://wrap.warwick.ac.uk/73056/.
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We study terminal 3-fold divisorial extractions σ: (E Y ) → (C X) which extract a prime divisor E from a singular curve C centred at a point P in a smooth 3-fold X. Given a presentation of the equations defining C, we give a method for calculating the graded ring of Y explicitly by serial unprojection. We compute some important examples and classify such extractions when the general hyperplane section SX containing C has a Du Val singularity at (P ∈ SX) of type A1, A2, D2k, E6, E7 or E8.
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Leach, Sarah Marks. "Postoperative Analgesic Effect of Intravenous Dexmedetomidine in Mandibular Third Molar Extractions." The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1443791551.
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Zgonnik, Viacheslav. "Elle & il : enantioselective liquid-liquid extraction and ionic liquids." Toulouse 3, 2011. http://thesesups.ups-tlse.fr/1297/.
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L'extraction liquide-liquide énantiosélective (ELLE) consiste en l'extraction d'un énantiomère à partir d'un mélange racémique par transfert entre deux phases liquides. Cette technologie est très prometteuse pour l'obtention des composés énantiopurs et devient l'objet d'une forte attention les dernières années grâce au développement de l'équipement approprié qui permet de réduire le temps et le prix de la séparation des énantiomères. L'objectif essentiel pour l'introduction d'ELLE dans le monde industriel est la découverte d'hôtes chiraux fiables, peu chers, durables, sélectifs et applicables à une large gamme de substances chirales. Dans ce travail, la possibilité d'effectuer l'ELLE dans un milieu ionique chiral a été vérifiée. De nombreux nouveaux liquides ioniques chiraux ont été préparés pour jouer le rôle des hôtes chiraux. Le meilleur exemple montre un excès énantiomérique de 30% et une sélectivité opérationnelle de 1,97. Ceci représente le premier exemple d'ELLE utilisant les liquides ioniques chiraux et sans usage d'ions métalliques<br>Enantioselective liquid-liquid extraction (ELLE) is an implementation of the extraction of one enantiomer from a racemic mixture by the transfer between two liquid phases. This technology is very promising for obtaining enantiopure compounds and becomes the object of much attention in recent years after the development of appropriate equipment that reduces the time and cost of the separation of enantiomers. The major objective for the successful introduction of ELLE to industrial world is the discovery of reliable, inexpensive and durable chiral hosts selective for a wide range of chiral substances. In this work the possibility of performing ELLE in chiral ionic liquids environment was verified. Many new chiral ionic liquids were prepared to play the role of chiral hosts. The best example shows enantiomeric excess of 30% and operational selectivity of 1. 97. This represents the first example of using chiral ionic liquids in ELLE and without metallic ions
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Bassil, Joseph. "Origine et processus de libération du sélénium dans l'aquifère carbonaté du site expérimental hydrogéologique de Poitiers." Thesis, Poitiers, 2014. http://www.theses.fr/2014POIT2332/document.
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La problématique environnementale du sélénium est principalement liée à son domaine de concentration très étroit entre toxicité et carence, et à sa présence diffuse au-delà des limites de potabilité dans de nombreux aquifères. Ainsi, des teneurs en sélénium supérieures à la norme européenne (10 ppb) ont été détectées dans les eaux souterraines du Site Expérimental Hydrogéologique (SEH) de Poitiers, dont le comportement hydrodynamique est particulièrement bien caractérisé. Le couplage d'études géochimiques, minéralogiques et pétrographiques a mis en évidence que les matériaux de remplissage (« argiles noires ») des structures karstiques subhorizontales présentes dans l'aquifère du Dogger au niveau du SEH, riches en sélénium et considérés comme la source potentielle du sélénium dissous dans ce réservoir, étaient issus de dépôts continentaux ayant subi des phases réductrices. Des fractionnements granulométriques et chimiques d'échantillons d'« argiles noires » ont montré que la fraction séléniée était principalement sous forme de sélénites dans la matrice et "associée" à la fraction organique soluble en milieu alcalin de nature majoritairement aliphatique. Des tests de lixiviation ont mis en évidence l'impact très important des conditions acido-basiques sur la quantité de sélénium dissous et sur la nature des espèces séléniées libérées dans les eaux. Les cinétiques de libération du sélénium tendent à montrer l'existence de trois processus principaux et les suivis de dissolution d'espèces majoritaires suggèrent que les mécanismes de libération du sélénium mis en jeu dans le contexte de l'étude sont principalement régis par des processus d'échange ou de complexation de surface<br>The environmental issue of selenium is mainly related to the narrow range between its deficiency and toxicity concentrations, and to its widespread presence beyond the limits of potability in many aquifers. Selenium concentrations above the European standard (10 ppb) were detected in the groundwater of the Hydrogeological Experimental Site (HES) of Poitiers, whose hydrodynamic behavior is particularly well characterized.The coupling of geochemical, mineralogical and petrographic investigations showed that black argillaceous sediments that fulfill subhorizontal karstic cavities present in the Dogger aquifer at the SEH and considered as the potential source of dissolved selenium in the groundwater, are continental deposits that have been transformed in reduced environments.Grain-sized and chemical fractionations of these "black clays" showed that selenium is mainly present as selenite in the geological matrix and is "associated" with the alkali soluble organic fraction which is predominantly aliphatic.Leaching tests have highlighted the important impact of acid-base conditions on the amount of dissolved selenium and on the nature of selenium species released into the water. The release kinetics of selenium tends to show the existence of three main processes. The major species dissolutions suggest that the selenium release mechanisms are mainly governed by exchange process or surface complexation
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Dalrymple, Iain Faculty of Science UNSW. "An approach to the optimisation of partial extractions for use in geochemical exploration." Awarded by:University of New South Wales, 2007. http://handle.unsw.edu.au/1959.4/40473.
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Geochemical exploration for mineral deposits has generally been restricted to regions dominated by residual regolith or where transported regolith cover is thin. A variety of partial geochemical extraction techniques, linked to new predictive models for element migration through transported regolith cover, have demonstrated a potential to detect deeply buried mineralisation under certain circumstances. Problems with the reliability and further development of such partial extractions are linked to the lack of information on either the form of metals or the factors that control the extraction of metals from regolith materials. This study quantitatively examines the mechanisms of a range of partial extraction methods, based on a suite of surface regolith samples from the Mandamah Cu-Au deposit that is covered by 50m of transported regolith. Samples at were subjected to acetate, hydroxylamine.HCI and Na-pyrophosphate extractions at various reagent concentrations, pH values, temperatures and durations, following various sample preparation and chemical pretreatment permutations. The data were modelled, and reaction conditions subsequently optimized, on the basis of central composite designs. Conventional partial extraction (acetate, hydroxylamine and aqua regia) data, displayed high variability for some major and trace metals surrounding the periphery of mineralisation at Mandamah but little indication of direct vertical migration of ore-related metals. The buffered acetate extraction is primarily controlled by the capacity of the solution to generate acid rather than exchange induced by the cation ofthe acetate salt. Trace metals were highly susceptible to readsorption effects. Acidic hydroxylamine extraction is driven by kinetically limited acid hydrolysis and the hydroxylamine concentration has little effect on metal extractability. Alkaline Na-pyrophosphate extraction proved difficult to model. Two new partial extractions developed in this study - alkaline hydroxylamine.HCI and pH-static calcium nitrate - offer a different functionality to conventional extractions and provide more coherent geochemical patterns at Mandamah related to the location of buried mineralisation. These patterns are also related to the capacity of samples to resist pH neutralization. Systematic optimisation of geochemical extraction procedures is demonstrated to be an effective approach to improving detection of geochemical patterns in surface regolith that can be spatially related to the effects of mineralisation on the chemistry and mineralogy of overlying transported regolith cover.
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Seneshen, David Michael. "The applicability of partial extractions to mineral exploration in areas of transported overburden." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ35977.pdf.
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Vroome, Kyle M. "Anterior alveolar bone changes following premolar extractions : a cone beam computed tomography evaluation /." Oklahoma City : [s.n.], 2009.
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Maria, Fábio Rogério Tôrres. "Frequência dos diferentes protocolos de extrações nos tratamentos ortodônticos conduzidos na Faculdade de Odontologia de Bauru FOB-USP, nos últimos 35 anos." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/25/25134/tde-02062011-143725/.
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O presente estudo objetivou realizar um levantamento retrospectivo de todos os planejamentos ortodônticos realizados pelo Departamento de Ortodontia (FOB USP) desde 1973, para que pudessem ser avaliados os protocolos de tratamento escolhidos à época, principalmente quanto à decisão de extrações e suas freqüências. A amostra constitui-se inicialmente de 3745 documentações ortodônticas arquivadas pelo Departamento de Ortodontia, das quais 332 documentações foram descartadas seguindo alguns fatores de exclusão, tais como casos transferidos, desistências e informações e exames incompletos. A amostra total de 3413 pacientes foi avaliada de acordo com o protocolo de tratamento escolhido, classificados como: Protocolo 0 (Sem extrações); Protocolo 1 (Extrações de 4 primeiros pré-molares); Protocolo 2 (2 primeiros pré-molares superiores e 2 segundos inferiores); Protocolo 3 (2 pré-molares superiores); Protocolo 4 (4 segundos pré-molares); Protocolo 6 (Incisivos e caninos); Protocolo 7 (Primeiros e segundos molares); Protocolo 8 (extrações atípicas); Protocolo 9 (grupo de agenesias e perdas precoces). Estes protocolos aferidos, foram então divididos em 7 grupos, definidos como 7 intervalos cronológicos a cada 5 anos: Intervalo 1 (1973-1977); Intervalo 2 (1978-1982); Intervalo 3 (1983-1987); Intervalo 4 (1988-1992); Intervalo 5 (1993-1997); Intervalo 6 (1998-2002); Intervalo 7 (2003-2007). Estes intervalos foram então comparados entre si para que as freqüências dos protocolos pudessem definir possíveis tendências predominantes a cada época testada. Os resultados demonstraram diferenças estatisticamente significantes para 7 dos 10 protocolos avaliados entre os intervalos considerados, evidenciando uma grande diferença de freqüência dos principais protocolos de tratamento ao longo destes 35 anos avaliados. Portanto conclui-se que a escolha pelos protocolos de tratamento sofreram influências de filosofias e dogmas vigentes durante os intervalos avaliados.<br>The purpose of this retrospective study was to evaluate all orthodontic treatment plannings conducted at the Orthodontic Department at Bauru Dental School, University of São Paulo, since 1973, in order to investigate extraction and nonextraction frequency protocols selected at each considered period. The sample comprised initially 3745 records of treated patients, that according to exclusion criteria, reduced the final sample to 3413 documentations. This total sample was evaluated according to the protocol choice, being divided into 10 groups: Protocol 0 (nonextraction group); Protocol 1 (4-first premolar extractions); Protocol 2 (2-maxillary first and 2-mandibular second premolar extractions); Protocol 3 (2-maxillary premolar extractions); Protocol 4 (4-second premolar extractions); Protocol 5 (asymmetric premolar extractions); Protocol 6 (incisor and canine extractions); Protocol 7 (first and second molar extractions); Protocol 8 (atypical extractions) and Protocol 9 (agenesis and previously missing teeth group). These 3413 obtained protocols were divided into seven 5-year intervals: Interval 1 (1973-1977); Interval 2 (1978-1982); Interval 3 (1983-1987); Interval 4 (1988-1992); Interval 5 (1993-1997); Interval 6 (1998-2002); Interval 7 (2003-2007). The frequency of each protocol was compared among the 7 intervals, using the Proportion Test, in order to identify some predominant trends at each tested period. The results showed that 7 frequency protocols were significantly different among the 7 considered intervals, evidencing that the protocols choice was influenced by some dominant philosophies or dogmas during the evaluated periods.
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Bastardis, Roland. "Dérivations et extractions de hamiltoniens modèles pour l'étude de composés à propriétés électroniques remarquables." Toulouse 3, 2007. http://thesesups.ups-tlse.fr/82/.
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L'objectif de cette thèse est d'identifier les mécanismes microscopiques responsables des propriétés macroscopiques de quelques composés magnétiques moléculaires et cristallins. Une première partie est consacrée aux méthodes ab initio explicitement corrélées permettant l'étude de ces composés. Nous proposons une méthode originale pour introduire les effets de la polarisation dynamique par une série de calculs SCF contraints. Dans un second temps, nous montrons comment la méthode des fragments immergés combinée à la théorie des hamiltoniens effectifs permet d'extraire de façon rationnelle et contrôlée des hamiltoniens modèles susceptibles de reproduire les propriétés macroscopiques. Nous nous intéressons tout d'abord aux déviations isotropes des hamiltoniens de Heisenberg pour lesquelles nous proposons un nouveau hamiltonien incluant un opérateur à trois corps susceptible de changer les propriétés collectives. Le chapitre suivant compare les capacités des hamiltoniens de double échange, de Heisenberg, et de Hubbard à reproduire la physico-chimie des manganites dopés. Il est démontré que la physique d'un hamiltonien de Hubbard est contenue dans les hamiltoniens plus simples de double échange et de Heisenberg, dans le cas d'un dimère de Mn ponté par un oxygène, et que les expressions des énergies obtenues avec ces deux derniers hamiltoniens sont équivalentes. Enfin, nous montrons que seul un hamiltonien de double échange, tenant compte à la fois des états non-Hund et d'une contribution antiferromagnétique de type Heisenberg, décrit correctement la physique de ces composés<br>The goal of this thesis is to identify the microscopic mechanisms responsible for the macroscopic of molecular and crystalline magnetic compounds. A first part is devoted to the explicitly correlated ab initio methods allowing the study of such compounds. We propose an original method to introduce the dynamical polarization effects though a series of constrained SCF calculations. Then we show how the embedded cluster method combined with the effective Hamiltonian theory makes possible the rational and controlled extraction of model Hamiltonians likely to reproduce the macroscopic properties. We are interested in the isotropic deviations from Heisenberg behavior and propose a new Hamiltonian including a three-body operator susceptible to change the collective properties. The following chapter compares the capabilities of the double exchange, Heisenberg and Hubbard Hamiltonians to reproduce the chemical physics of doped-manganites. It is shown that the physics of a Hubbard Hamiltonian is contained in the simpler double exchange and Heisenberg Hamiltonians, in the case of a Mn dimer bridged by an oxygen, and that the energy expressions obtained from these last two Hamiltonians are analytically identical. Finally, we show that only a double exchange Hamiltonian, taking account both non-Hund state effects and a Heisenberg antiferromagnetic contribution, accurately describes the microscopic physics of these compounds
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Paris, Alice. "Extractions et analyses des hydrocarbures aromatiques : approches méthodologiques et applications à des matrices fruitières." Thesis, Normandie, 2017. http://www.theses.fr/2017NORMC246/document.
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Les hydrocarbures aromatiques monocycliques (BTEX) et polycycliques (HAP) sont pour la plupart reconnus pour leur toxicité via ingestion. Le suivi de leur contenu dans les matrices alimentaires est donc indispensable. Plusieurs approches sensibles et complémentaires ont été établies, avec la pomme comme modèle d’étude, pour la double détermination de ces hydrocarbures aromatiques volatils et semi-volatils au niveau du µg/kg.Une micro-extraction en phase solide dans l’espace de tête (HS-SPME) a été utilisée pour l'extraction des hydrocarbures aromatiques les plus légers (MM entre 78 et 178 g/mol). La récupération des composés les plus lourds (MM entre 202 et 278 g/mol) a quant à elle été permise par une méthodologie basée sur l'extraction assistée par les ultrasons (UAE) suivie d'une extraction en phase solide (SPE). Une alternative plus sensible à cette stratégie combinant l’HS-SPME et l’UAE/SPE pour la détermination globale des hydrocarbures aromatiques a également été développée. Le remplacement de l’étape de SPE par une micro-extraction sur solide compacté (MEPS) a permis une récupération plus rapide, sensible et plus large des HAP (MM entre 152 et 278 g/mol).L’ensemble des stratégies d'extraction, associées à des analyses en chromatographie gazeuse couplée à la spectrométrie de masse, a ensuite pu être appliqué à la détermination des 20 composés aromatiques ciblés dans des pommes récoltées en Normandie ou des fruits provenant du commerce contaminés ou non par des gaz d’échappement ou des fumées de combustion de biomasse. Ces applications ont révélé la faible contamination des pommes normandes étudiées, l’adsorption prédominante des composés aromatiques au niveau de la peau des fruits et leur faible transfert vers la chair<br>Monocyclic aromatic hydrocarbons (BTEX) and polycyclic aromatic hydrocarbons (PAHs) are considered and recognized as toxic compounds via ingestion. Their monitoring in food product is thus a significant concern. Sensitive and complementary experimental approaches were investigated with apple as model for the dual determination of volatile and semi-volatile aromatic hydrocarbons at the ppb level.A solid-phase micro-extraction in the headspace of samples (HS-SPME) was used for the most volatile aromatic hydrocarbons (MW between 78 and 178 g/mol). The recovery of the least volatile aromatic hydrocarbons (MW between 202 and 278 g/mol) was implemented with an ultrasound assisted extraction (UAE) followed by a purification step using a solid phase extraction (SPE). The methodology consisting in HS-SPME and UAE/SPE enabled the global determination of BTEX and PAHs. The SPE step was then substituted by a micro-extraction with a packed sorbent (MEPS) to elaborate a most sensitive and rapid methodology for the quantification of a wider range of PAHs (MW between 152 and 278 g/mol).Extraction procedures associated with analyses using gas chromatography and mass spectrometry were then applied to the determination of 20 targeted aromatic compounds in apples harvested in Normandy or in commercial fruits exposed or not exposed to exhaust gas or to wood smoke. These applications revealed low levels of contaminants in the studied apples from Normandy. A predominant adsorption of aromatic compounds occurs on the skin of fruits and the transfer to the pulp is almost inexistent
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Gravier, Pierre. "Orthodontie en technique linguale : traitement d'une malocclusion de classe ii division 1 d'angle avec extractions." Lyon 1, 1992. http://www.theses.fr/1992LYO1D064.
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Kang, Jinah. "Retrospective Three-dimensional facial soft tissue analysis in skeletal Class I malocclusions with premolar extractions." Master's thesis, Temple University Libraries, 2018. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/512008.
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Oral Biology<br>M.S.<br>Objectives: Decreased volume and atrophy are hallmarks of aging facial soft tissues. In perioral region, a hallmark is deepening of nasolabial folds. It is unknown how extraction orthodontic treatment affects such tissues. This study describes nasolabial fold regional changes in premolar extraction cases. Methods: Pre- and post-treatment 3dMD images of 14 skeletal Class-I patients with 4 premolar extractions were studied for changes of tissue thickness in the nasolabial fold region. All subjects were treated at Temple University. The sample consisted of 10 females and 4 males aged 12 -26 years old and included three ethnicities: Asian, Hispanic, and African American. With the aid of 3dMD Vultus software, both qualitative and quantitative analyses were collected. Color histograms were created for qualitative analyses, and quantitative volumetric changes in cheek volume were correlated to 2-D cephalometric lip thickness, lip retraction, and incisor retraction. Data were analyzed by Spearman’s rho for lip thickness, lip retraction, and incisor retraction. Regression analyses were completed controlling for age, gender, and ethnicity. Results: In this sample of Class-I malocclusion patients with 4 premolar extraction treatment, quantitative results showed no significant correlations were found between 2-D soft tissue thickness and volumetric changes around the nasolabial fold region. Moreover, none of the other characteristics including, change in the upper lip in 2-D cephalometric measurements, age, and gender were factors that correlated with volumetric changes around the nasolabial fold. The qualitative findings showed changes in lips and commissures did not affect the soft tissues around the nasolabial fold areas. Overall, there were no significant correlations between the thickness of soft tissue, change in the lips in 2-D, age, ethnicity, and gender in volumetric changes. Conclusions: Data generated by this investigation did not imply any cause-and-effect relationship between measurements of lip thickness, lip retraction, and incisor retraction to the deepening of the nasolabial fold.<br>Temple University--Theses
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VIGNES-GUETTET, PASCALE. "Incidents secondaires aux extractions dentaires a visee prophylactique cardio-vasculaire : etude prospective concernant 98 patients." Lyon 1, 1991. http://www.theses.fr/1991LYO1M141.
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Pichon, Valentin. "Méthodes extractives, analytiques et d'améliorations de la biodisponibilité des principes actifs contenus dans le Cannabis sativa L." Electronic Thesis or Diss., Limoges, 2024. http://www.theses.fr/2024LIMO0059.
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Les plantes sont utilisées depuis des millénaires pour les traitements médicinaux. Cannabis sativa L. est une plante très controversée, classée comme stupéfiants dans la majorité des pays. Les phytocannabinoïdes, métabolites secondaires sécrétés dans ses trichomes, ont la capacité de se fixer sur les récepteurs CB1 et CB2 du système endocannabinoïde de l’homme. Ce système participe à la régulation de multiples fonctions physiologiques de notre organisme, tels que la régulation de la douleur, de l’appétit etc. Le tétrahydrocannabinol (THC) ou cannabidiol (CBD) admettent donc des potentiels thérapeutiques en concentrations contrôlées. Ces travaux de thèse s’inscrivent au sein de l’expérimentation du cannabis thérapeutique sous l’égide de l’ANSM en France. Dans une première partie, l’ensemble des expériences ont été préparées sur une plante modèle, Humulus lupulus L. appartenant également au cannabacées. Dans une seconde partie, une variété « THC dominant » de Cannabis sativa L. a été soumise à de multiples méthodes extractives (SE, UAE, MAE, PLE) permettant l’étude des rendements massiques (≈25%). Des dosages colorimétriques ont établis les TPC, TFC, TCC, TCCa et le pouvoir antioxydants des extraits. Les molécules volatiles ont été étudiées par HS-SPME-GC-MS et les phytocannabinoïdes par quantifications et déréplication (GNPS et SIRIUS) en LC-MS/MS. Les séparations et purifications ont permis d’obtenir le THCA, Δ-9THC, Δ-8THC et le CBN, dont la structure moléculaire a été vérifiée par RMN 1D et 2D. Des études statistiques (Désirabilité globale, TOPSIS) et plan d’expérience (DSD) ont permis d’établir les meilleures extractions en fonction de l’ensemble des résultats précédents. Enfin, des essais de formulation conformes à la Pharmacopée Européenne ont été réalisés proposant des comprimés sublinguaux de CBD<br>Plants have been used for medicinal treatments for thousands of years. Cannabis sativa L. is a controversial plant, classified as a narcotic in most countries. Phytocannabinoids, secondary metabolites secreted in trichomes, have the ability to bind to CB1 and CB2 receptors in the human endocannabinoid system. This system is involved in regulating many of our body's physiological functions, such as pain and appetite. Tetrahydrocannabinol (THC) and cannabidiol (CBD) therefore have therapeutic potential in controlled concentrations. This thesis work is part of the experimentation with therapeutic cannabis under the aegis of the ANSM in France. In the first part, all the experiments were carried out on a model plant, Humulus lupulus L., also belonging to the Cannabaceae. In the second part, a 'THC dominant' variety of Cannabis sativa L. was subjected to multiple extractive methods (SE, UAE, MAE, PLE) to study mass yields (≈25%). Colorimetric assays established the TPC, TFC, TCC, TCCa and antioxidant power of the extracts. Volatile molecules were studied by HS-SPME-GC-MS and phytocannabinoids by quantification and dereplication (GNPS and SIRIUS) in LC-MS/MS. Separations and purifications yielded THCA, Δ-9THC, Δ-8THC and CBN, whose molecular structure were verified by 1D and 2D NMR. Statistical studies (Global Desirability, TOPSIS) and experimental design (DSD) were used to establish the best extractions based on all the previous results. Lastly, formulation tests in compliance with the European Pharmacopoeia were carried out on CBD sublingual tablets
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Da, Fonte Kévin. "Des plantes oubliées à la parfumerie moderne : extraction, caractérisation et reproduction olfactive pour le développement d'ingrédients." Electronic Thesis or Diss., Université Côte d'Azur, 2025. http://www.theses.fr/2025COAZ5003.
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Ce projet de recherche, réalisé en collaboration avec L'Occitane en Provence et le Musée International de la Parfumerie, a pour but d'étudier des plantes oubliées de la parfumerie afin de développer de nouveaux ingrédients pour la parfumerie moderne. Tout d'abord, une base de données de ces plantes, développée lors d'une thèse précédente, a été améliorée. À partir de cette base de données, 25 plantes ont été sélectionnées pour être étudiées lors d'une phase de criblage, permettant l'extraction des composés odorants stockés à l'aide de méthodes telles que l'hydrodistillation, l'entrainement à la vapeur, l'extraction par solvants et l'extraction au CO₂ supercritique. Les extraits obtenus ont été caractérisés olfactivement, et leurs composés (semi-)volatils ont été analysés par DI-GC-MS/FID ou HS-SPME-GC-MS. Certaines plantes ont été écartées d'un potentiel développement en ingrédient parfum en raison de contraintes liées au marketing, à la réglementation ou à l'approvisionnement. À l'issue de ce criblage, 4 plantes d'intérêt ont été sélectionnées pour une étude approfondie. Une approche basée sur l'extraction (semi-)quantitative des composés volatils émis par les plantes a été explorée pour recréer leur odeur. Dans cette approche, envisagée principalement pour surmonter les difficultés d'approvisionnement, les composés volatils ont été capturés et analysés à l'aide de la DHS-ATD-GC-MS. L'objectif était d'identifier les composés odorants et de déterminer leurs proportions relatives, afin d'assister le parfumeur dans la formulation d'un ingrédient parfum reproduisant le plus fidèlement possible l'odeur de ces plantes. Parmi les plantes d'intérêt, l'une d'entre elles a montré un potentiel significatif de valorisation mais a suscité des questions en matière d'identification botanique. Des études macroscopiques, stéréomicroscopiques, olfactives et chimiotaxonomiques réalisées sur plusieurs spécimens ont permis d'identifier trois souches différentes. En associant les résultats des analyses chimiques obtenus par HS-SPME-GC-MS sur les parties aériennes de la plante aux analyses olfactives, et en utilisant des réseaux moléculaires, des molécules clés responsables de descripteurs olfactifs d'intérêt ont été identifiées. De plus, cette même plante a été utilisée pour développer une méthode de reproduction de l'odeur par DHS-ATD-GC-MS, assistée par des plans d'expériences. La HS-SPME-GC-MS a également contribué à l'identification de certains composés extraits par DHS<br>This research project, conducted in collaboration with L'Occitane en Provence and the International Perfume Museum, aims to study forgotten perfumery plants to develop new ingredients for modern fragrances. First, a database of these plants, developed during a previous thesis, was enhanced. Based on this database, 25 plants were selected to be studied during a screening phase involving the extraction of stored odorant compounds through methods such as hydrodistillation, steam distillation, solvent extraction, and supercritical CO₂ fluid extraction. The resulting extracts were then olfactorily evaluated for their fragrance potential, and their composition of (semi-)volatile compounds were analyzed using DI-GC-MS/FID or HS-SPME-GC-MS. Some plants were excluded from perfume ingredient development due to marketing, regulatory, or sourcing considerations. Following this screening phase, 4 plants of interest were selected for further study. An approach based on the (semi-)quantitative extraction of volatile compounds emitted by the plants was explored to recreate their scent. This approach, primarily considered to overcome supply challenges, involved capturing and analyzing the volatile compounds using DHS-ATD-GC-MS. The objective was to identify the odorant compounds and determine their relative proportions to assist the perfumer in formulating a fragrance ingredient that most faithfully reproduces the scent of these plants. Among the plants of interest, one demonstrated significant potential for valorization but raised questions regarding its botanical identification. Macroscopic, stereomicroscopic, olfactory, and chemotaxonomic studies conducted on several specimens led to the identification of three distinct strains. By correlating the results of chemical analyses obtained using HS-SPME-GC-MS on the aerial parts of the plant with olfactory analyses and utilizing molecular networks, key molecules responsible for desirable olfactory descriptors were identified. Furthermore, this same plant was used to develop a method for scent reproduction using DHS-ATD-GC-MS, supported by experimental designs. HS-SPME-GC-MS also contributed to the identification of certain compounds extracted through DHS
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Jacquat, Olivier. "Long-term fate of zinc in contaminated soils : zinc speciation by synchrotron spectroscopy and chemical extractions /." Zürich : ETH, 2008. http://opac.nebis.ch/cgi-bin/showAbstract.pl?sys=000259330.
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Lawlor, Alan James. "Experimental measurements and modelling of metal binding by environmental solids before and after selective chemical extractions." Thesis, Lancaster University, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.431460.
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Feldman, Esther. "Changes in the occlusal curves secondary to serial sextractions compared to late premolar extractions and controls." Thesis, University of British Columbia, 2014. http://hdl.handle.net/2429/46842.
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Objectives: To determine the relationships between tooth tipping and occlusal curvature patterns in serial extraction (SE) cases versus late premolar extraction (LPE) cases and controls.
Methods: Mandibular dental casts and cephalometric radiographs were collected from 90 subjects (30 Class I controls, 30 SE cases, 30 LPE cases) at 3 time points: baseline (T0) for controls and SE, after natural drift/pre orthodontics (T1) for controls, SE, and LPE, and after comprehensive orthodontic treatment (T2) for the SE and LPE groups. The casts were scanned and rendered as virtual models. 12 cusp tips (4 incisors and 2 first molars) were digitized and the occlusal curves were measured using Rhinoceros by fitting a sphere to the landmarks (least-squares method). Radiographs were digitized and the long axes of the central incisor, canine, and first molar were landmarked and related to palatal plane to determine the direction and amount of tipping.
Results: The SE group differed significantly from the other two groups at T1, with smaller radii in 2/3 outcomes. From T0-T1, the SE group showed a tendency for the incisor and canine to tip distally, while the molar tipped mesially. From T1-T2, the SE group had smaller radii versus LPE and demonstrated mesial tipping of the incisor and canine angulations, with the molar tipping distally.
Conclusions: SE cases tend to have steeper occlusal curves (smaller radii), post tooth drift and after orthodontic treatment as compared to the other groups. In general, orthodontic treatment, post SE, involved incisor and canine proclination, as well as molar uprighting. SE is unlikely to save more than 4-6 months of active treatment due to the time needed to correct the increased occlusal curvature that results from this procedure.
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Ferrato, Marc. "Extractions des auxiliaires organiques de mise en forme d'une poudre céramique à l'aide de fluides supercritiques." Limoges, 1995. http://www.theses.fr/1995LIMO0035.
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Un appareillage destine a l'etude de l'extraction des liants organiques utilises en technologie ceramique a ete concu et realise. Il a permis l'etude de la solubilisation des liants et plastifiants les plus frequemment utilises. L'approche empirique de hildebrand a ete utilisee pour prevoir la solubilite des auxiliaires organiques de mise en forme dans le solvant. Elle a ete confrontee a l'experience et a permis l'optimisation des conditions de solubilisation. Une composition de mise en forme, a base de polystyrene et de poudre d'alumine, adaptee au deliantage supercritique a ete developpee. La cinetique de l'extraction supercritique a ete modelisee. La diffusivite des especes organiques solubilisees au travers de la preforme ceramique impregnee de co2 supercritique a ete calculee dans differentes conditions de pressions et de temperatures
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Sajjadi, Seyed Mohammad Hossein. "Étude des extractions de composés organiques à l'aide de liquides ioniques et nanoparticules d'oxydes de métaux." Thesis, Université de Lorraine, 2013. http://www.theses.fr/2013LORR0223/document.
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Le travail de thèse porte sur l'utilisation simultanée de liquides ioniques (LIs) et de nanoparticules d'oxydes de métaux (NPs) pour l'extraction des composés organiques à partir des solutions aqueuses et organiques. Il a été constaté que les LIs présentent une excellente sélectivité par rapport aux composés organiques. Cette sélectivité a été souvent améliorée par la présence de NPs. Deux techniques d'utilisation des systèmes extractifs NPs/LIs ont été utilisées; La première consistait à l'extraction liquide/liquide à partir d'une phase aqueuse par une phase LI contenant suspension de NPs. Dans la seconde méthode les nanoextracteurs NPs/LI ont été dispersés directement en solution. La qualité des résultats dépend de tous les paramètres du système étudié (la nature du solvant, du LI, des NPs et du composé organique extrait). Nous nous sommes également intéressés au mécanisme de formation d'agrégats de NPs en solutions aqueuses contenant des liquides ioniques. Nous avons démontré que les nanoagrégats de NPs peuvent être souvent considérés comme nanoextracteurs imbibés de liquides ioniques et actifs en tant qu'extracteurs. Nous avons démontré l'utilité du système NPs/LI pour l'extraction de composés organiques. Des nombreux tests ont permis d'établir les conditions dans lesquelles cette technique peut conduire à des résultats satisfaisants. L'utilisation de nanoextracteurs parait très prometteuse pour élimination de solutés très dilués<br>This study concerns a simultaneous utilization of ionic liquids (Ils) and nanoparticles of metal oxides (NPs) to extracting organic compounds from aqueous and organic solutions. It was observed that the selectivity of organic compounds extracted with ILs makes is excellent and that may be enhanced when IL was used together with NPs. Two techniques were used to enhance the selectivity. At first, the liquid-liquid extraction was performed using a IL phase containing NP suspension in contact with an aqueous or organic phase. Secondly, the nanoextractors NPs/IL were directly dispersed in solution. The quality of results obtained was a complex function of ILs, NPs and organic compounds to be extracted. The mechanism of NP aggregate formation in aqueous solutions of ILs was also studied. It was demonstrated that the nanoaggregates formed with NPs are soaked with ILs and may act as IL nanoextractors. Results presented demonstrated that NPs/IL systems may be useful in extraction of organic compounds. Indeed, numerous extraction experiments made it possible to define optimal conditions to carry out successful extractions. The most promising results were obtained with extraction of diluted solutes
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Dou, Lixin. "Applications of Bayesian inference methods to time series data analysis and hyperfine parameter extractions in Mossbauer spectroscopy." Thesis, University of Ottawa (Canada), 1999. http://hdl.handle.net/10393/8483.
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The Bayesian statistical inference theory is studied and applied to two problems in applied physics: spectral analysis and parameter estimation in time series data and hyperfine parameter extraction in Mossbauer spectroscopy. The applications to spectral analysis and parameter estimation for both single- and multiple-frequency signals are presented in detail. Specifically, the marginal posterior probabilities for the amplitudes and frequencies of the signals are obtained by using Gibbs sampling without performing the integration, no matter whether the variance of the noise is known or unknown. The best estimates of the parameters can be inferred from these probabilities together with the corresponding variances. When the variance of the noise is unknown, an estimate about the variance of the noise can also be made. Comparisons of our results have been made with results using the Fast Fourier Transformation (FFT) method as well as Bretthorst's method. The same numerical approach is applied to some complicated models and conditions, such as periodic but non-harmonic signals, signals with decay, and signals with chirp. Results demonstrate that even under these complicated conditions the Bayesian inference and Gibbs sampling can still give very accurate results with respect to the true result. Also through the use of the Bayesian inference methods it is possible to choose the most probable model based on known prior information of data, assuming a model space. The Bayesian inference theory is applied to hyperfine parameter extraction in Mossbauer spectroscopy for the first time. The method is a free-form model extraction approach and gives full error analysis of hyperfine parameter distributions. Two applications to quadrupole splitting distribution analysis in Fe-57 Mossbauer spectroscopy are presented. One involves a single site of Fe3+ and the other involves two sites for Fe3+ and Fe2+. In each case the method gives a unique solution to the distributions with arbitrary shape and is not sensitive to the elemental doublet parameters. The Bayesian inference theory is also applied to the hyperfine field distribution extraction. Because of the complexity of the elemental lineshape, all the other extraction methods can only use the first order perturbation sextet as the lineshape function. We use Blaes' exact lineshape model to extract the hyperfine field distribution. This is possible because the Bayesian inference theory is a free-form model extraction method. By using Blaes' lineshape function, different cases of orientations between the electric field gradient principle axis directions and the magnetic hyperfine field can be studied without making any approximations. As an example the ground state hyperfine field distribution of Fe65Ni35 Invar is extensively studied by using the method. Some very interesting features of the hyperfine field distribution are identified.
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Dou, Lixin. "Applications of Bayesian inference methods to time series data analysis and hyperfine parameter extractions in Mössbauer spectroscopy." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape9/PQDD_0020/NQ45170.pdf.
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Fairhurst, Robert. "Designing molecularly imprinted polymeric phases for sensors, separations and high throughput extractions : spherical and thin-film polymers." Thesis, University of East Anglia, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.423395.
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Brisset, Patrick. "Étude de la pollution mécanique des rivières par les extractions de granulats : application au cas du Doubs." Toulouse, INPT, 1986. http://www.theses.fr/1986INPT088H.
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L'extraction de granulats du milieu aquatique s'accompagne de la mise en suspension de matières minérales très fines et de matières organiques. Celles-ci, souvent liées aux argiles pour former le complexe argilo-humide modifient la composition physico-chimique de l'eau, la morphologie et la nature des fonds et perturbent ainsi l'équilibre écologique du site. Pour pouvoir évaluer l'impact des rejets sur l'environnement, une bonne connaissance des suspensions introduites artificiellement dans l'écoulement par l'opération de dragage du lit est nécessaire. Les matériaux, mis en suspension par le dragage, s'ajoutent à ceux présents naturellement dans la rivière. Ainsi il est important de distinguer suspensions naturelles et suspensions polluantes. La suspension naturelle est celle existant dans une rivière en dehors de toute action extérieure. Les suspensions naturelles correspondent à un régime établi, fonction du régime hydraulique de la rivière et respectent la condition de bon mélange. La suspension polluante est constituée de matériaux qui n'auraient jamais été mis en suspension sans une action extérieure. Elle n'est pas corrélée aux conditions hydrauliques.
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Brisset, Patrick. "Etude de la pollution mécanique des rivières par les extractions de granulats application au cas du Doubs /." Grenoble 2 : ANRT, 1986. http://catalogue.bnf.fr/ark:/12148/cb37617749j.
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MacKriel, Earl Ari. "Changes in arch dimensions after extraction and non-extraction orthodontic treatment." Thesis, University of the Western Cape, 2008. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_4464_1260523586.
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<p>The aim of this study was to determine whether there are changes in the interdental arch widths and arch lengths of the mandibular and maxillary arches during nonextraction and extraction orthodontic treatment. The records of 78 patients treated by one orthodontist were used for this study. Three treatment groups were selected: a nonextraction group (Group NE), a group treated with extraction of maxillary and mandibular first premolars (Group 44), and a group treated with extraction of maxillary first premolars and mandibular second premolars (Group 45). The arch width measurements were measured in the inter-canine, inter-premolar and inter-molar areas. The arch length was measured as the sum of the left and right distances from mesial anatomic contact points of the first permanent molars to the contact point of the central incisors or to the midpoint between the central incisor contacts, if spaced.</p>
<p>Statistical analysis included descriptive statistics of the data, analysis of the correlation matrices, Wilcoxon Signed Rank tests and Kruskal-Wallis tests of the changes which occurred during treatment. The intercanine widths in the mandible and maxilla increased during treatment in all three groups, with the extraction groups showing a greater increase than Group NE (p<<br>0.05). In Group NE the mandibular arch length increased (p<<br>0.05), while the maxillary arch length remained essentially unchanged. Both extraction groups showed decreases in arch length in the dentitions (p<<br>0.05), with greater decreases occurring in the maxilla. The difference in arch length change between the two extraction groups was not significant (p><br>0.10). The inter-canine arch width increased in all three treatment groups, more so in the two extraction groups. From this it is evident that extraction treatment does not necessarily lead to narrowing of the dental arches in the canine region. The inter-second premolar arch width decreased in both extraction groups. Non-extraction treatment resulted in an increase in the inter-premolar and inter-molar arch widths.</p>
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Gras, Matthieu. "Recyclage de métaux venant d'accumulateurs NiMH : développement d'extractions liquide-liquide sélectives à partir de liquides ioniques." Thesis, Université Grenoble Alpes (ComUE), 2018. http://www.theses.fr/2018GREAI053/document.
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Les accumulateurs nickel-hydrure métallique (NiMH) dominent actuellement le marché du stockage de l’énergie pour les véhicules hybrides. On estime à 1 milliard, le nombre de batteries NiMH produites chaque année. En fin de vie, le taux de recyclage de ces déchets électroniques reste faible, bien que la technologie NiMH contienne des quantités importantes de métaux onéreux et stratégiques. Deux grandes familles d’éléments chimiques coexistent sous forme de composés intermétalliques dans l’électrode négative: les métaux de transitions (TM) (Ni, Co, Mn et Fe) ainsi que les terres rares (REE) (La, Ce, Nd et Pr). Parmi les TM, le cobalt présente une criticité accrue. En effet, les minerais issus de réserves naturelles ne permettront pas de couvrir la demande croissante en cobalt liés au développement des technologies émergentes. Les REE produits à plus de 97 % en Chine sont au cœur des préoccupations de l’Union Européenne qui depuis 2010 pointe du doigt des techniques d’extractions dévastatrices pour l’environnement. C’est dans le but de répondre aux problématiques économiques et environnementales que le projet a été construit en associant l’entreprise de recyclage de batteries Recupyl® au laboratoire académique LEPMI grâce au financement du Labex CEMAM. L’objectif de ce travail est de proposer un procédé avec un faible impact environnemental pour le recyclage des métaux à partir de véritables accumulateurs NiMH. Pour cela, le remplacement de solvants volatiles organiques par des liquides ioniques, plus respectueux des principes de la ‘chimie verte’ sera étudié. En s’appuyant sur des procédés innovants d’extraction liquide-liquide et de récupération des éléments par hydrométallurgie et par électrochimie nous proposons une voie de valorisation des métaux présents dans ces batteries<br>Nickel-metal hydride (NiMH) batteries are currently dominating the market of energy storage in hybrid electric vehicles. 1 billion cells are estimated to be produced each year. In their end-of-life, these electronical wastes exhibit low recycling rates, despite the fact that NiMH batteries contain high amounts of valuable and strategic metals. Two main metal families coexist as an intermetallic compound in negative electrodes: transition metals (TM) (Ni, Co, Mn and Fe) and rare earth elements (REE) (La, Ce, Nd and Pr). Among TM, cobalt exhibits the highest criticality rate. Indeed, natural ores will not cover the increasing cobalt demand linked to emerging technologies. REE produced at more than 97 % in China are at the centre of European Union’s preoccupations. To tackle economic and environmental issues, this project, supported by the labex CEMAM is a partnership between the company Recupyl® and the academic laboratory LEPMI. It aims at investigating on low environmental impact routes for the recycling of metals present in real spent NiMH batteries. This requires the replacement of volatile organic compounds by ionic liquids, respecting the principles of ‘green chemistry’. Based on innovative extraction and recovery processes of elements by hydrometallurgy and electrochemistry, we propose a flowsheet for the valorisation of metals from those batteries
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Chehayeb, Karim Malek. "Numerical fixed-effectiveness and fixed-area models of the humidification dehumidification desalination system with air extractions and injections/." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/92147.
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Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2014.<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references (pages 101-104).<br>The humidification dehumidification (HDH) desalination system can be advantageous in small-scale, off-grid applications. This system is very robust and can tolerate a wide range of feed salinities, making it a good candidate for treating produced water from hydraulically fractured natural gas wells. The main drawback of this technology has been its low energy efficiency, which results in high water production costs. This work focuses on the thermodynamic balancing of HDH. The first part uses a fixed-effectiveness approach to model the use of multiple air extractions and injections to thermodynamically balance the HDH system, so as to make it more energy efficient. The effect of the number of extractions on several performance parameters is studied. In addition, we study the effect of the enthalpy pinch, which is a measure of performance for a heat and mass exchanger, on these performance parameters. Further, we present results that can be used as guidelines in designing HDH systems. These results include the identification of appropriate temperatures for the extracted/injected air streams, the division of the heat duty between stages, and the value of the mass flow rate ratio in each stage at various values of enthalpy pinch. Fixing the effectiveness of the heat and mass exchangers allows them to be modeled without explicitly sizing the components and gives insight on how the cycle design can be improved. However, linking the findings of fixed-effectiveness models to actual systems can be challenging, as the performance of the components depends mainly on the available surface areas and the flow rates of the air and water streams. In the second part of this study, we present a robust numerical solution algorithm for a heat and mass transfer model of a complete humidification-dehumidification system consisting of a packed-bed humidifier and a multi-tray bubble column dehumidifier. We look at the effect of varying the water-to-air mass flow rate ratio on the energy efficiency of the system. In addition, we study the effect of the top and bottom temperatures on the performance of the system. We recommended the implementation a control system that varies the mass flow rate ratio in order to keep the system balanced in off-design conditions, especially with varying top temperature. Finally we consider a single air extraction, and look at the effect of the location of extraction, and its direction. We define the criteria for achieving a completely balanced system.<br>by Karim Malek Chehayeb.<br>S.M.
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Scheetz, Caleb David. "Dissolution, Transport, and Fate of Lead on Shooting Ranges." Thesis, Virginia Tech, 2003. http://hdl.handle.net/10919/9856.
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Shooting ranges concentrate significant quantities of heavy metals, especially lead as spent shot and bullets, on very small parcels of land. Samples taken from a shooting range near Blacksburg, VA, USA provide information about the reservoirs and pathways of lead at shooting ranges in an upland setting and humid environment. Metallic lead corrodes rapidly and develops a coating of corrosion products. The type and amount of corrosion products found on lead shot and bullets are best understood through examination of Eh-pH relationships. X-ray diffraction analysis identified hydrocerussite (Pb₃(CO₃)₂(OH)₂) as the corrosion phase present on lead shot recovered from the range. Hydrocerussite dissolution can produce soluble lead concentrations ranging from 2 ppb to 2 ppm for the soil pH values at this site. This soluble lead is captured by the soil. Sequential chemical extractions revealed that vertical lead migration beyond the A-horizon was minimal. The bound-to-Fe & Mn oxides and bound-to-carbonates soil fractions were identified as significant reservoirs for sequestration of lead in the soil. The highest concentration of extractable lead contained in the soil was directly correlated with the highest concentration of lead shot and bullets measured on the shotgun range surface. The geochemical framework for understanding the corrosion process, identifying the corrosion product(s) that control lead solubility, and identifying the geochemical barriers to lead migration that were employed at the Blacksburg, VA shotgun range, provides a basis for selecting best management practices for this and other shooting ranges.<br>Master of Science
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Noirot, Pierre-Antoine. "Logiciels d'étude et de prévision des extractions par solvants : application à la valorisation des solutions de chlorure de nickel." Lille 1, 1985. http://www.theses.fr/1985LIL10129.
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L'extraction liquide-liquide des métaux connaît un développement spectaculaire lié à la nécessité de traiter des minerais toujours plus pauvres ou plus complexes, ainsi qu'à la demande de métaux de pureté croissante. Afin de maîtriser cette opération tout en réduisant les expérimentations préliminaires, un modèle général a été proposé pour la prédiction des équilibres de partage. Il s'appuie sur les phénomènes réels et ne présente aucune restriction quant aux mécanismes ou à la composition ionique de la phase aqueuse. Les paramètres caractéristiques sont les concentrations des réactants, les constantes thermodynamiques des espèces formées ainsi que les coefficients d'interaction nécessaires au calcul des coefficients d'activité. Des logiciels de simulation des données et d'affinement des paramètres inconnus ont été réalisés. Ils ont été appliqués à l'étude de l'extraction de Co2+, Cu2+ et Mn2+, en milieu chlorure (NiCl2, LiCl) par un système extractant composé de tri-iso-octylamine, d'un tiers solvant et d'un diluant hydrocarboné. Une représentation très fidèle des données expérimentales est obtenue, permettant des extrapolations d'une excellente fiabilité. Le modèle a été utilisé pour le calcul et l'optimisation des installations d'extraction à contre courant, grâce à un programme approprié. Divers agencements ont ainsi été testés, en vue de la séparation de Co2+, Cu2+ et de Mn2+, des solutions industrielles de chlorure de nickel.
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Deschamps, Thomas. "Extractions de courbes et surfaces par méthodes de chemins minimaux et ensembles de niveaux : applications en imagerie médicale 3D." Paris 9, 2001. https://portail.bu.dauphine.fr/fileviewer/index.php?doc=2001PA090038.
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Dans cette these nous nous interessons a l'utilisation des méthodes de chemins minimaux et des méthodes de contours actifs par Ensembles de Niveaux, pour l'extraction de courbes et de surfaces dans des images medicales 3D. Dans un premier temps, nous nous sommes attaches a proposer un éventail varié de techniques d'extraction de chemins minimaux dans des images 2D et 3D, basees sur la résolution de l'équation Eikonal par l'algorithme du Fast Marching. Nous avons montre des resultats de ces techniques appliquees a des problèmes d'imagerie médicale concrets, notamment en construction de trajectoires 3D pour l'endoscopie virtuelle, et en segmentation interactive, avec possibilité d'apprentissage. Dans un deuxieme temps, nous nous sommes interessés a l'extraction de surfaces. Nous avons developpé un algorithme rapide de pré-segmentation, sur la base du formalisme des chemins minimaux. Nous avons étudié en détail la mise en place d'une collaboration entre cette méthode et celle des Ensembles de Niveaux, dont un des avantages communs est de ne pas avoir d'a priori sur la topologie de l'objet a segmenter. Cette méthode collaborative a ensuite ete testée sur des problèmes de segmentation et de visualisation de pathologies telles que les anevrismes cerebraux et les polypes du colon. Dans un troisième temps nous avons fusionné les résultats des deux premières parties pour obtenir l'extraction de surfaces, et des squelettes d'objets anatomiques tubulaires. Les squelettes des surfaces fournissent des trajectoires que nous utilisons pour déplacer des cameras virtuelles, et nous servent a definir les sections des objets lorsque nous voulons mesurer l'étendue d'une pathologie. La dernière partie regroupe des applications de ces méthodes a l'extraction de structures arborescentes. Nous étudions le cas des arbres vasculaires dans des images médicales 3D de produit de contraste, ainsi que le problème plus difficile de l'extraction de l'arbre bronchique sur des images scanners des poumons<br>In this thesis, we focus on the use of minimal path techniques and Level-Sets active contours, for curve and shape extraction in 3D medical images. In the first part of thesis, we worked upon the reduction of the computing cost for path extraction. We proposed several path extraction algorithms for 2D as well as for 3D images. And we applied those techniques to real medical imaging problems, in particular automatic path extraction for virtual endoscopy and interactive and real-time path extraction with on-the-fly training. In the second part, we focused on surface extraction. We developed a fast algorithm for pre-segmentation, on the basis of the minimal path formalism of the first part. We designed a collaborative method between this algorithm and a Level-Sets formulation of the problem, which advantage is to be able to handle any topological change of the surfaces segmented. This method was tested on different segmentation problems, such as brain aneurysms and colon polyps, where target is accuracy of the segmentation, and enhanced visualization of the pathologies. In the last part of the thesis, we mixed results from previous part to design a specific method for tubular shape description and segmentation, where description is the extraction of the underlying skeleton of our objects. The skeletons are trajectories inside our objects, which are used as well for virtual inspection of pathologies, as for accurate definition of cross-sections of our tubular objects. In the last chapter we show applications of our algorithms to the extraction of branching structures. We study the vascular tree extraction in contrast enhanced medical images, and we apply the same principle to the more complex problem of the bronchial tree extraction in multi-slice CT scanners of the lungs
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Julyan, Johan Christian. "Soft tissue profile changes in patients treated with non-extraction versus second premolar extraction protocols - using the Damon system." University of the Western Cape, 2018. http://hdl.handle.net/11394/6374.
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Magister Scientiae Dentium - MSc(Dent) (Orthodontics)<br>Orthodontic treatment has the ability to improve the aesthetics and the function of
patients. In order to create space, orthodontic treatment often requires removal of
teeth. The most common teeth removed for orthodontic treatment are the
premolars. It has become popular to remove second premolars in certain cases
where the soft tissue profile should not be altered.
The Damon self-ligating orthodontic system is renowned for not requiring dental
extractions in the majority of cases. The effect of extractions on the soft tissue
profile of patients, in conjunction with using the Damon system, has therefore not
been researched. It is important to understand the effect that orthodontic treatment
and extractions can have on the soft tissue profile of patients. This effect can
accurately be determined by making use of the soft tissue cephalometric analysis,
developed by Dr Reed A. Holdaway in 1983.
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Spielmann, Eugen [Verfasser], Roland [Gutachter] Span, and Mandy [Gutachter] Gerber. "Anaerobic digestion of algal residues from supercritical carbon dioxide extractions / Eugen Spielmann ; Gutachter: Roland Span, Mandy Gerber ; Fakultät für Maschinenbau." Bochum : Ruhr-Universität Bochum, 2019. http://d-nb.info/1182682278/34.
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Sahmoune, Amar. "Extractions synergiques de metaux divalents de transition par association d'une acyl-4-pyrazolone-5 avec des polyethers cycliques et acycliques." Université Louis Pasteur (Strasbourg) (1971-2008), 1988. http://www.theses.fr/1988STR13116.
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Extractions de co. Zu. Cd et cu divalents par les melanges phenyl-1 methyl-3 benzoyl-4 pyrazolone-5 ethers crown. La coextraction alcalins-alcalinoterreux complexes par les composes crown et des metaux divalents est possible quand la taille de la cavite de l'ether-crown est voisine de celle de l'alcalin (ou alcalino-terreux) et quand l'ion ml::(3)**(-) est suffisamment stable
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Goodwin, Michaela. "The use of general anaesthetic for dental extractions in children : researching the complex causal networks and approaches to reducing need." Thesis, University of Manchester, 2015. https://www.research.manchester.ac.uk/portal/en/theses/the-use-of-general-anaesthetic-for-dental-extractions-in-children-researching-the-complex-causal-networks-and-approaches-to-reducing-need(eb277cce-f90a-4ce5-b62c-91873a7d2959).html.
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Dental decay remains a global issue but, in the UK, has become concentrated within the most vulnerable section of society, namely young children and the most deprived. When dental decay and subsequent infection become too severe, teeth may need to be extracted under General Anaesthetic. The aim of this work was to develop a greater understanding of the population of young children referred for a Dental General Anaesthetic (DGA) in the North West of England and to explore possible interventions that may positively impact on this group reducing the high number of children undergoing this procedure. A mixed methods approach was utilised, combining a broad scoping review, quantitative data collection and qualitative interviews. Individually these methods were used to develop a greater understanding of the issue and of the services, processes and patients involved in DGA. The methods were subsequently combined using triangulation to address potential preventative interventions that would be appropriate and acceptable to this group. Differences were observed between hospitals in treatment experiences of children across the North West of England. These included variations in the environment, hospital setting and time from referral to treatment, all of which were shown to impact on the child. The number of children experiencing a repeat DGA was also high and noted as an area that required further intervention. While DGA could be a distressing experience it was considered necessary and resulted in a positive outcome both in terms of oral health and a child’s quality of life. Improving oral health in young children who experience severe decay is a complex and challenging area. A number of interventions were identified that could reduce the need for extraction under DGA. These ranged from targeted interventions, linked to information provision and enablement to support those who are more at risk, to policy change with regard to excessive sugar in food and beverages that could have a broader impact across the population. In addition, DGA service re-designs are discussed including increased provision of prevention that may benefit children referred along this pathway and thereby reduce repeat DGA rates in the future.
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Sahmoune, Amar. "Extractions synergiques de métaux divalents de transition par association d'une acyl-4-pyrazolone-5 avec des polyéthers cycliques et acycliques." Grenoble 2 : ANRT, 1988. http://catalogue.bnf.fr/ark:/12148/cb37618386w.
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