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1
Astutik, Wynda. "IPR Modeling for Coning Wells". Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for petroleumsteknologi og anvendt geofysikk, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-19518.
Testo completoAbstract (sommario):
In this study, based on the work of Vogel, we generated the Inflow Performance Relationship (IPR) curves and its dimensionless form at any stage of depletion using black-oil simulator results. The IPR was generated for horizontal well with gas and water coning problems, producing from thin oil reservoir sandwiched between gas cap and aquifer. Two empirical IPR equations adopted from SPE paper by Whitson was also presented here. The first empirical relationship was developed based on simulated data for each reservoir pressure (stage of depletion) while the second relationship was developed based on all generated data.A fully implicit black-oil Cartesian model with total grid number of 1480 and 150 ft total thickness was used as reservoir model. The horizontal well extends through the full length of reservoir in y-direction with only one grid number along the horizontal section which makes the model a 2D problem. Sensor reservoir simulator and Pipe-It software were utilized to generate the IPR data.This work also includes a sensitivity study to understand the effect of several parameters to gas and water coning behavior, well placement optimization, coning collapse study, and the effect of coning to maximum well production rate. In coning collapse study, a relationship between flowing bottom-hole pressure and reservoir pressure when the cone collapse is provided in graphical form. This could be useful in field application where chocking the well to lower flowing bottom-hole pressure has become one alternative to reduce coning problems.
2
Ronen, Jonathan. "Boundary Control of the Gas Coning Problem". Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for teknisk kybernetikk, 2010. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-11460.
Testo completoAbstract (sommario):
This thesis was set to tackle the gas coning problem in oil-rim reservoirs with horizontal wells. The focus was short term production planning in the sub-critical phase only. Different controllers were developed and assessed based on the objective of net-present-value (NPV) of oil produced in the sub-critical phase.The reservoir model is a 1-D partial differential equation describing the dynamics of the gas-oil contact (GOC), for a homogeneous reservoir. Gas coning is considered to be the deformation of the GOC towards the well.Several controllers were developed and assessed alongside control laws from previous research: (i) the Backstepping method was used to develop a state-feedback controller, along with an observer. Coupled they make the Backstepping output-feedback controller. (ii) an output-feedback controller based on the structure proposed by previous research. (iii) linear-quadratic optimal control.An extended Kalman filter was also considered as a state observer, alongside the Backstepping observer.The backstepping controller did not deliver an increase of sub-critical payout which warrants the complicated structure of an observer-controller pair. It was even outperformed by simpler, output-feedback control laws. The optimal linear-quadratic controller achieved the best NPV of sub-critical production by far. This makes it the most attractive control strategy presented, even when considering that a real-world implementation will need to be paired with a state observer.
3
Okon, Anietie Ndarake. "WATER CONING IN FRACTURED RESERVOIRS: A SIMULATION STUDY". Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for petroleumsteknologi og anvendt geofysikk, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-19598.
Testo completoAbstract (sommario):
Water coning is a complex phenomenon that depends on a large number of variables which include among others: production rate, perforation interval, mobility ratio, capillary pressure, etc. Its production can greatly affect the productivity of a well and the reservoir at large. In fractured reservoirs, the phenomenon is more complex owing to the high permeability of the fractures in the porous media. With this complexity in mind, water coning behaviour in fractured reservoir was studied by simulating a reservoir supported by a strong aquifer using ECLIPSE-100 Black-Oil Simulator. The water cut (WCT), oil production rate (OPR) and water saturation (BWSAT) at the producing interval (Block 1, 1, 7) were used to evaluate the coning phenomenon in a fractured reservoir. In the course of the study, sensitivity analyses on the modelled reservoir’s anisotropy ratio (kv/kh), production rate (q), storativity capacity (ω), fracture width (b) and fracture permeability (kf) were conducted to evaluate their effect on coning behaviour in fractured reservoir. The results obtained depict that while the anisotropy ratio is very significant in water cut and water saturation at the perforating interval it has no adverse effect on oil production rate. It was however, observed that the water cut and oil production rate decreased as the production rate (q) increased. Furthermore, the water cut, oil production rate and water saturation (BWSAT) from the fractured reservoir is sensitive to the storativity capacity (ω) depending on the fracture porosity (φf). Conversely, the fracture’s width (b) and permeability (kf) have no significant effect on the coning behaviour of the modelled fracture reservoir. However, anisotropy ratio (kv/kh), production rate as well as storativity capacity (ω) are significant parameters in evaluating coning phenomenon in fractured reservoirs.
4
Ayeni, Kolawole Babajide. "Empirical modeling and simulation of edgewater cusping and coning". Texas A&M University, 2008. http://hdl.handle.net/1969.1/85948.
Testo completoAbstract (sommario):
In many cases, it is important to predict water production performance of oil
wells early in, or maybe before, their production life. In as much as oil field water is
important for pressure maintenance purposes and displacement of oil towards the
perforation of the producing well, excessive water production leads to increased cost. In
the case when no provision is made, it represents a significant liability. The case
considered here is a well producing from a monocline with an edge-water aquifer.
Although such problems can be computed with reservoir simulation, the objective of this
work was to develop an empirical method of making water production predictions.
The reservoir model was described as a single well producing from the top of a
monocline drainage block with water drive from an infinite-acting aquifer. During the
reservoir simulation runs, water would cusp and cone into the well, increasing water
production and decreasing oil production. A number of simulation runs were made,
varying eleven model variables. Typical model variables include dip angle, formation
thickness and production rate. For each run a modified Addington-style plot was made. The relationship between each model parameter and three graphical variables was used
to develop the set of empirical correlations. The empirical correlations developed were
integrated with some derived equations that relate important reservoir parameters and
incorporated into a computer program.
The developed correlations and program can be used to carry out sensitivity
analysis to evaluate various scenarios at the early planning stages when available
reservoir data are limited. This gives a quick and easy method for forecasting production
performance with an active edge-water drive. Furthermore, the approach developed in
the research can be applied to other water production problems in other fields/reservoirs.
The developed program was validated and used to evaluate synthetic and field cases.
Overall, a good match was achieved.
5
Shevchenko, Egor. "Experimental study of water coning phenomenon in perforated pipes geometry". Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for energi- og prosessteknikk, 2013. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-23086.
Testo completoAbstract (sommario):
This Master Thesis is performed in close cooperation between NTNU and Statoil Research Centre in Rotvoll, Trondheim. It focuses on the experimental study of the water coning phenomenon in perforated pipe geometry. This study refers to Statoil data on horizontal well design, geometry of the ICD/AICD housing, production rates and fluid properties.The experimental facilities were designed during the autumn semester in the project ?Experimental setup for water coning in horizontal annular pipe geometries?. It is based on the 2D-configuration setup and was used for flow visualization experiments.The study provides extensive literature review of the problem. It describes existing industry experience and shows available academic research in the area of the coning phenomenon. Detailed hazard identification and risk assessments analysis were performed according to the NTNU and SINTEF safety procedures prior to starting of the work in the lab. The necessary measures for risk reduction were implemented. The event, possibly compromising safety level of the experimental runs, was documented and investigated in order to prevent similar reoccurrences in future.The total number of 459 experiments with different rig and oil/water flow setup was conducted. Results are presented in clear graphical form in excel spreadsheet attached to the thesis. It shows key trends in oil/water flow behaviour in the gap towards a drainage hole, representing reservoir fluid inflow into the well tubing through the Inflow Control Device (ICD). Discussion part puts emphasis on the explanation of the obtained results and provides important input to improve the design of ICD.
6
Khalili, Ali Petroleum engineering UNSW. "A review of critical coning rate correlations and identifying the most reliable equation". Awarded by:University of New South Wales. Petroleum engineering, 2005. http://handle.unsw.edu.au/1959.4/22388.
Testo completoAbstract (sommario):
The study of coning in oil production is important because of huge water production associated with oil production around the world each year. Estimation of critical coning rate has been the subject of numerous studies and a number of correlations have been reported. This study presents a review of the current available methods for estimating critical coning rate for both vertical and horizontal wells. The various methods and correlations are compared and the assumptions on which they are based evaluated. Following comparison made between the correlations, the most reliable theories are identified for both vertical and horizontal wells separately. Among the correlations for vertical wells, this study recommends two implicit methods presented by Wheatley and Azar Nejad et al. They determined the oil potential distribution influenced by water cone with a remarkable accuracy. For horizontal wells, two methods, Joshi???s equation and Rechem et al formula, are considered to be the most reliable. Joshi???s equation provides lower estimates than Chaperon???s correlation in which the water cone effect on oil potential was neglected. The Recham et al formula also gives a similar result. On the whole, the Rechem et al method is preferred.
7
Couper, Christine Judith. "Morphology and physiology of bud development and coning in Pinus contorta Dougl". Thesis, University of Edinburgh, 1987. http://hdl.handle.net/1842/12010.
Testo completo
8
Selmi, Mohamed. "Resonance phenomena in viscous fluid configurations inside a spinning and coning cylinder". The Ohio State University, 1991. http://rave.ohiolink.edu/etdc/view?acc_num=osu1300360400.
Testo completo
9
Johnson, David Craig. "A coning motion apparatus for hydrodynamic model testing in a non-planar cross-flow". Thesis, Massachusetts Institute of Technology, 1989. http://hdl.handle.net/10945/25780.
Testo completoAbstract (sommario):
As part of continuing research into the flow about slender bodies of revolution, a coning motion apparatus for hydrodynamic model testing was built and demonstrated. This is the first known use of a rotary balance apparatus for external flow hydrodynamic applications. The vorticity shed by the hull and appendages creates a wake field that interacts with the velocity distribution over the vehicle's surface. This in turn effects the surface pressure distribution and thus, when integrated over the body's surface, the total force on the hull/appendage combination. It is this interaction that prevents a closed-form analytic solution to the problem. Keywords: Fluid mechanics. (JES)
10
Isemin, Isemin Akpabio. "Numerical Simulation of Gas Coning of a Single Well Radial in a Naturally Fractured Reservoir". Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for petroleumsteknologi og anvendt geofysikk, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-19275.
Testo completoAbstract (sommario):
Gas coning is the tendency of the gas to drive oil downward in an inverse cone due to the downward movement of gas into the perforations of a producing well thereby reducing oil production and the overall recovery efficiency of the oil reservoir. This work addresses gas coning issues in a naturally fractured reservoir via a numerical simulation approach on a single-well radial cross-section using the ECLIPSE 100 reservoir simulator. Matrix and fracture properties are modelled. Critical rate, breakthrough time and GOR after breakthrough is determined which is used to investigate the effect of matrix and fracture properties on gas coning effective reservoir parameters such as oil flow rate, matrix and fracture porosity, vertical and horizontal matrix and fracture permeability, matrix block size, etc. Results show that reservoir parameters that affect coning include oil flow rate, matrix and fracture porosity, matrix and vertical permeability, anisotropy ratio, perforated interval thickness, density difference and mobility ratio. While matrix block size and fracture spacing have no significant effect on gas coning.
11
Crawford, C. A. "Advanced engineering models for wind turbines with application to the design of a coning rotor concept". Thesis, University of Cambridge, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.598134.
Testo completoAbstract (sommario):
The primary theoretical contribution of this work is an enhanced Blade Element Momentum (BEM) method. Utilizing vortex theory to model induction, computationally efficient corrections are derived that are key in more accurately predicting performance for coned rotors. The theory is extended to include wake expansion, dynamic inflow, and yawed conditions, as well as considering centrifugal and radial-flow induced stall-delay. The theory is favourably validated against Computational Fluid Dynamics (CFD) and experimental results for both real and idealized rotors. BLADEDTM was to be modified with the enhanced BEM method for dynamic analyses. To support these analyses, a beam sectional model and Finite Element Method (FEM) approach to the generalized centrifugally stiffened beam problem were implemented. Ultimately, the linear structural theory in current codes precluded accurate predictions at large flap angles. In lieu of a fully non-linear flexible-body simulation, a rigid-body dynamic model of the system was developed. The coupled aerodynamic and structural models were then used to analyse steady-state and dynamic operation, including optimal control schedules. Parametric optimization studies were used to examine the interplay between design variables for the coning rotor, relative to a reference conventional machine. Increased blade length, shape and airfoil choice were found to be tightly coupled, yielding energy gains of 10-30% over conventional rotors. Airfoil choice and control mechanism were found critical to limiting torque and thrust. The fundamental non-linear open-loop dynamics were also examined, including flap and edgewise damping behaviour. Low-Frequency Noise (LFN) was computed with a properly implemented physics-based model, to quantify sensitivity to design and operational parameters. The current work is a preliminary, but critical step, in proving the worth of the coning rotor. Controlled design and an accurate flexible-body code will be required for full load-set simulations, to affect detailed component design and costing. Ultimately, prototype testing will be needed to validate the complicated stalling behaviour of the coning rotor.
12
De, Coning Gerhard. "Service delivery to governmental and commercial environments with specific reference to Gerotek as a public entity / Gerhard L. de Coning". Thesis, North-West University, 2005. http://hdl.handle.net/10394/712.
Testo completoAbstract (sommario):
Striving towards service excellence, a public entity can embark on various
service and product delivery strategies as well as functional management
strategies or management tools. The primary objective of this study is to
indicate to what extent a public entity such as Gerotek can meet the different
approaches to economically viable service delivery to the government and
commercial environments respectively, where different rules, regulations,
means and ways of contracting apply.
In order to realise this objective, the characteristics of public entities and those
of private entities competing in the same market were explored and
comparisons made between the different entities to indicate the level of
success each one is able to achieve. Public-Private Partnerships, Project-
Partnering and Management, as well as Black Economic Empowerment
involvement, as different forms of partnership agreements or other forms of
business models, were investigated to distinguish best practice in service and
product delivery strategies. The effectiveness of various management tools
was discussed, such as the South African Excellence Model, Total Quality
Management, and the Balanced Scorecard, which can be applied to assist
management in improving service delivery.
Interviews were conducted according to an interviewer-administered
questionnaire to obtain information pertaining to the literature study of the
above, in order to determine the effectiveness of service delivery within a
public entity competing in government and commercial environments. The
respondents agreed that a public entity could meet best practice to deliver
economically viable services and products to both environments, with the
reservation that continuous improvements should be made.Thesis (M. Development and Management)--North-West University, Potchefstroom Campus, 2005.
13
De, Coning Gerhard Lourens. "An integrated service excellence model for strategic military test and evaluation facilities : the case of the South African National Department of Defence / Gerhard L. de Coning". Thesis, North-West University, 2009. http://hdl.handle.net/10394/4138.
Testo completoAbstract (sommario):
Capital-intensive military test and evaluation facilities that are governed within the public entity domain need to deliver effective and efficient services in meeting or exceeding the Department of Defence's requirements and in retaining strategic defence capabilities and technologies. Various business and operational processes currently exist in these facilities, without any common quality assurance, control and performance management systems. The primary objective of this study was to develop an integrated service excellence model in order to obtain and continuously improve service excellence in the services provided by these strategic military test and evaluation facilities, ensuring that all activities necessary to design, develop and implement a test and evaluation service are effective and efficient.
In order to develop an integrated service excellence model, various management tools and approaches to improve quality in the search for service excellence were identified and described. Total Quality Management (TQM), Business Process Re-engineering (BPR), the South African Excellence Model (SAEM) and the Balanced Scorecard (BSC), amongst other productivity and quality models, were researched and evaluated and tested through an empirical study conducted at the various test and evaluation facilities. Financial, human resources and environmental challenges facing the facilities in obtaining service excellence within the boundaries of public governance were explored in order to build the solutions to these challenges into the integrated service excellence model. Effective and efficient deployment of the facilities' resources, as well as the development and incorporation of safety, health and environmental policies and management standards were discussed and measured against national legislation. Applicable military, industrial and commercial quality standards and specifications, such as the International Organisation for Standardisation (ISO) quality management standards and the Republic of South Africa (RSA) military standards, were explored as the burden is on the facilities not only to obtain official accreditation to render specific test and evaluation services, but also to maintain accreditation and to execute the services against these standards.
As corporate governance is a multi-faceted subject impacting on economic efficiency and shareholder's welfare, much emphasis was placed on governance principles through the identification of a framework and governance objectives in which the test and evaluation facilities operate. Good governance characteristics, such as discipline, transparency, independence, accountability, responsibility, fairness and social responsibility, were identified through the King 2 Report.
This study was conducted amongst senior and top management of the test and evaluation facilities and amongst members of the Department of Defence through an interviewer-administered questionnaire comparing information and data on theory on service excellence, quality management, performance management, governance principles with the interviewer-questionnaire responses to performance indicators at these facilities. Management perceptions and management recommendations contributed to the development of the integrated service excellence model as well as to the future implementation of the model. It was evident through the study that no such integrated model exists to address the test and evaluation needs of the Department of Defence.Thesis (Ph.D. (Public Management and Administration))--North-West University, Potchefstroom Campus, 2009.
14
Picenoni, Mathias. "La minoranza di confine grigionitaliana : confini soggettivi, comportamento linguistico e pianificazione linguistica /". Coira : Bündner Monatsblatt, 2008. http://opac.nebis.ch/cgi-bin/showAbstract.pl?u20=9783905342451.
Testo completo
15
Lopera, Javier. "Aerodynamic Control of Slender Bodies from Low to High Angles of Attack through Flow Manipulation". Connect to Online Resource-OhioLINK, 2007. http://www.ohiolink.edu/etd/view.cgi?acc_num=toledo1177504352.
Testo completo
16
McKinney, Colin Bryan Powell. "Conjugate diameters: Apollonius of Perga and Eutocius of Ascalon". Diss., University of Iowa, 2010. https://ir.uiowa.edu/etd/711.
Testo completoAbstract (sommario):
The Conics of Apollonius remains a central work of Greek mathematics to this day. Despite this, much recent scholarship has neglected the Conics in favor of works of Archimedes. While these are no less important in their own right, a full understanding of the Greek mathematical corpus cannot be bereft of systematic studies of the Conics. However, recent scholarship on Archimedes has revealed that the role of secondary commentaries is also important. In this thesis, I provide a translation of Eutocius' commentary on the Conics, demonstrating the interplay between the two works and their authors as what I call conjugate. I also give a treatment on the duplication problem and on compound ratios, topics which are tightly linked to the Conics and the rest of the Greek mathematical corpus. My discussion of the duplication problem also includes two computer programs useful for visualizing Archytas' and Eratosthenes' solutions.
17
GONCALVES, LEANDRO DE SOUZA. "REFLECTIVE PROPERTIES OF CONICS". PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2014. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=25120@1.
Testo completoAbstract (sommario):
COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIORA ideia principal desta dissertação é apresentar as cônicas e demonstrar suas equações cartesianas bem como suas propriedades reflexivas. O trabalho está focado em abordar tais propriedades reflexivas com o auxílio do software GeoGebra.
The main idea of this dissertation is to present the conics and demonstrate their cartesian equations and their reflective properties. The work is focused on addressing such reflective properties with the aid of software GeoGebra.
18
Maurel, Agnès. "Instabilité d'un jet confiné". Paris 6, 1994. http://www.theses.fr/1994PA066771.
Testo completoAbstract (sommario):
Une etude experimentale et numerique est menee sur l'oscillation auto-entretenue d'un jet bidimensionnel dans une cavite rectangulaire. L'etude experimentale permet de preciser les differents regimes observes lorsque la vitesse d'entree du jet et la longueur de la cavite varient. Une etude plus detaillee du regime d'oscillations auto-entretenues est presentee. Elle met en evidence l'existence de modes (stages), caracterises par une longueur d'onde constante verifiant l=(n+1/4), ou l est la longueur de la cavite ; la valeur n selectionnee depend de la largeur d'entree du jet et de la vitesse d'entree du jet. Le mecanisme d'amplification presume est fonde sur un modele de synchronisation entre l'oscillation a la sortie de la cavite et les perturbations declenchees a l'entree du jet. L'etude numerique est menee sur une cavite carree (les simulations 2d sont effectuees avec le code de calcul nekton, fonde sur une methode d'elements finis spectraux) et s'attache a decrire l'instabilite proche du seuil. Une frequence fondamentale est degagee en regime lineaire et les non-linearites font apparaitre l'harmonique 2 et un mode stationnaire de frequence nulle ; elle modifie le motif de l'ecoulement moyen. Le developpement de cet ecoulement moyen est le mecanisme de saturation de l'instabilite oscillante: il stabilise les profils de vitesse. Une methode d'analyse en modes est presentee, qui tente de degager des grandeurs caracteristiques de l'instabilite. Les methodes d'exploitation des resultats des simulations sont applicables dans d'autres geometries et, en particulier, les resultats presentes dans cette these sont comparables a ceux mis en evidence dans des etudes numeriques du sillage
19
Levaché, Bertrand. "Dynamiques d'imbibition en milieu confiné". Phd thesis, Université Pierre et Marie Curie - Paris VI, 2014. http://pastel.archives-ouvertes.fr/pastel-00966910.
Testo completoAbstract (sommario):
Ce travail de thèse expérimental porte sur les dynamiques d'imbibition en milieu confiné. Cette situation survient lorsque un fluide mouillant les parois d'un solide vient déplacer un second fluides non-miscible. La divergence des contraintes visqueuses au niveau de la ligne de contact avec le solide complexifie la description de la forme et de la dynamique d'invasion du ménisque qui ne peut se résumer, même aux échelles macroscopique du confinement solide, à l'avancement d'un front liquide homogène. L'absence de longueur caractéristique intrinsèque aux fluides nécessite de tenir compte des couplages entre écoulement et forme des interfaces à toutes les échelles, depuis le nanomètre (interactions moléculaires) jusqu'à l'échelle du confinement (une centaine de micromètres dans nos expériences). Ce caractère multi-échelle est au centre des travaux effectués durant cette thèse. A l'aide du développement de nouveaux outils micro-fluidiques, nous étudions quantitativement l'imbibition dans une géométrie de type Hele-Shaw. Une étude à la fois expérimentale et numérique nous permet de mettre en évidence l'existence d'une nouvelle transition d'entrainement. Une étude complète du modèle numérique nous permet ensuite d'unifier ce nouveau mode avec celui reporté jusqu'à présent dans la littérature. Nous nous intéressons aussi à l'imbibition dans des réseaux poreux modèle. Nous identifions alors expérimentalement un nouveau mode d'invasion généralisant l'entrainement obtenu précédemment. Ce scénario est piloté par l'écoulement en film de coin autour des obstacles constituant le poreux. Nous proposons alors un critère géométrique simple pour discriminer les différents modes d'invasions.
20
Naeve, Trent Phillip. "Conics in the hyperbolic plane". CSUSB ScholarWorks, 2007. https://scholarworks.lib.csusb.edu/etd-project/3075.
Testo completoAbstract (sommario):
An affine transformation such as T(P)=Q is a locus of an affine conic. Any affine conic can be produced from this incidence construction. The affine type of conic (ellipse, parabola, hyperbola) is determined by the invariants of T, the determinant and trace of its linear part. The purpose of this thesis is to obtain a corresponding classification in the hyperbolic plane of conics defined by this construction.
21
Coudoro, Kodjo. "Etude expérimentale et modélisation de la propagation de flammes en milieu confiné et semi confiné". Thesis, Orléans, 2012. http://www.theses.fr/2012ORLE2005.
Testo completoAbstract (sommario):
Cette étude s’inscrit dans le cadre de l’évaluation du risque d’accélération de flamme en situation accidentelle. La méthodologie développée dans le cadre de l’évaluation du risque hydrogène dans l’industrie nucléaire a permis de proposer un critère permettant d’évaluer le risque d’accélération des flammes de prémélange hydrogène/air/diluants, sur la base des propriétés du mélange. L’objectif de cette étude est l’acquisition de données fondamentales relatives aux mélanges gaz naturel/air et gaz de synthèse/air puis l’extension de la méthodologie appliquée aux mélanges hydrogène/air à ces mélanges. Ainsi, trois mélanges gazeux ont été choisis et ont fait l’objet de cette étude. Il s’agit du G27 (82%CH4/18%N2), du G222 (77%CH4/23%H2), et du H2/CO (50%H2/50%CO). Au cours de ce travail les limites d’inflammabilités des mélanges ont été déterminées pour une température initiale de 300 K et une pression de 1 et 2 bars. Les vitesses fondamentales de flamme et les longueurs de Markstein ont été mesurées à différentes températures initiales (300, 330 et 360 K) et à deux pressions initiales (1 et 2 bar) pour chacun des mélanges. Une modélisation cinétique de la vitesse de flamme a été réalisée et a permis l’évaluation de l’énergie d’activation globale sur la base du modèle cinétique présentant le meilleur accord avec l’expérience. La propension des mélanges a s’accélérer fortement en présence d’obstacles a ensuite été caractérisée au cours de l’étude de l’accélération de flamme. Cette étude de l’accélération de flamme a permis de mettre en évidence que différents critères d’accélération s’appliquent selon que la flamme soit stable ou pas. Un critère permettant de prédire l’accélération de flamme a été proposée dans les deux casThe context of the current study is the assessment of the occurrence of flame acceleration in accidental situations. The methodology developed for the assessment of hydrogen hazard in the nuclear industry led to the definition of a criterion for the prediction of the acceleration potential of a hydrogen/air/dilutant mixture based on its properties. This study aims to extend this methodology to gaseous mixtures that can be encountered in the classical industry. Therefore, three mixtures were chosen: the first two are representatives of a natural gas/air mixture: G27 (82%CH4/18%N2) and G222 (77%CH4/23%H2). The third one is a H2/CO (50%H2/50%CO) mixture and represents the Syngas. During this work, flammability limits were measured at 300 K and two initial pressures (1 and 2 bar) for each mixture. Fundamental flame speeds and Markstein lengths were also measured at three initial temperatures (300, 330, 360 K) and 2 initial pressures (1 and 2 bar) for each mixtures. A kinetic modeling was performed based on three detailed kinetic models and allowed the calculation of the global activation energy on the basis of the kinetic model which showed the best agreement with the experimental data. The acceleration potential for each mixture in presence of obstacles has then been investigated. It was found that different criteria were to be applied depending on whether the flame is stable or not. A predicting criterion was proposed in both case
22
Nekes, Sandra [Verfasser], Franciscus [Gutachter] Coninx e Ad [Gutachter] Snik. "Equivalent Hearing Loss in Children / Sandra Nekes ; Gutachter: Franciscus Coninx, Ad Snik". Köln : Universitäts- und Stadtbibliothek Köln, 2016. http://d-nb.info/1122262310/34.
Testo completo
23
Tamez, Dorothy J. "Using commercial-off-the-shelf speech recognition software for conning U.S. warships". Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2003. http://library.nps.navy.mil/uhtbin/hyperion-image/03Jun%5FTamez.pdf.
Testo completoAbstract (sommario):
Thesis (M.S. in Information Technology Management)--Naval Postgraduate School, June 2003.Thesis advisor(s): Monique P. Fargues, Russell Gottfried. Includes bibliographical references (p. 71-74). Also available online.
24
Penfold, Elizabeth Lily. "To confine or not to confine? : an analysis of the messaging of the proposition 2 campaigns". Scholarly Commons, 2012. https://scholarlycommons.pacific.edu/uop_etds/818.
Testo completoAbstract (sommario):
This thesis employed a Historical-Critical method using rhetoric and framing theory to examine the 2008 Proposition 2: Prevention of Farm Animal Cruelty Act campaigns. The Californians for Humane Farms (HSUS) and Californians for SAFE Food (CSF) were the respective proponent and opponent coalitions analyzed in this thesis. The analysis examined sixteen campaign artifacts that were examples of how the proposition was communicated to California's voting populous. In Conjunction with the appeals and frames, the message strategies were analyzed as to how they allowed the HSUS and CSF to effectively communicate with voters. By using rhetoric and framing 4 theory this analysis was able to distinguish which rhetorical appeals effectively supported the campaigns. The analysis showed that the HSUS was successful with their campaign because of well-executed rhetorical appeals that created a concise message about animal confinement and animal cruelty issues.
25
Arnswaldt, Albrecht von. "De vicariatus controversia : Beiträge Hermann Conrings in der Diskussion um die Reichsverfassung des 17. Jahrhunderts /". Berlin : Duncker & Humblot, 2004. http://www.gbv.de/dms/spk/sbb/recht/toc/387559876.pdf.
Testo completo
26
La, Ciacera Giorgio. "Tomografia computerizzata a fascio conico (CBCT)". Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amslaurea.unibo.it/12315/.
Testo completoAbstract (sommario):
Questo elaborato tratta le apparecchiature per la tomografia computerizzata a fascio conico (CBCT). Inizialmente sono descritte le caratteristiche dei raggi X ed il loro utilizzo in campo clinico, analizzando le varie tipologie di radiografia. Successivamente, si introduce il tomografo computerizzato, del quale si descrive la struttura e i principi di funzionamento, fino ad arrivare alla trattazione dei sistemi CBCT. Di questi viene studiato il funzionamento, il meccanismo di formazione delle immagini, gli ambiti di applicazione e i rispettivi vantaggi e limiti. Infine si analizza la dose di radiazione X emessa dall'apparecchiatura, studiando se il paziente corra rischi sottoponendosi a questi esami radiologici.
27
Gustafsson, Lukas. "The Euclidean Distance Degree of Conics". Thesis, KTH, Matematik (Avd.), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-252533.
Testo completoAbstract (sommario):
The Euclidean Distance Degree (EDD) of a variety is the number of critical points of the squared distance function of a general point outside the variety. In this thesis we give a classification of conics based on their EDD, originally attributed to Cayley. We show that circles and parabolas have EDD 2 and 3 respectively while all other conics have EDD 4. We reduce the computation of the EDD to finding solutions of the determinant of a certain generalized matrix, called the hyperdeterminant of type 2 × 3 × 3. This determinant is computed using the celebrated Schläfli decomposition.The Euclidean Distance Degree (EDD) of a variety is the number of critical points of the squared distance function of a general point outside the variety. In this thesis we give a classification of conics based on their EDD, originally attributed to Cayley. We show that circles and parabolas have EDD 2 and 3 respectively while all other conics have EDD 4. We reduce the computation of the EDD to finding solutions of the determinant of a certain generalized matrix, called the hyperdeterminant of type 2 × 3 × 3. This determinant is computed using the celebrated Schläfli decomposition.
28
Descardeci, Jose Ricardo. "Antena de microfita sobre substrato conico". [s.n.], 1991. http://repositorio.unicamp.br/jspui/handle/REPOSIP/261183.
Testo completoAbstract (sommario):
Orientador : Attilio Jose GiarolaDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica
Made available in DSpace on 2018-07-14T01:51:52Z (GMT). No. of bitstreams: 1 Descardeci_JoseRicardo_M.pdf: 3868112 bytes, checksum: 2184fb222cc010a66c9430f3980954b0 (MD5) Previous issue date: 1991
Resumo: É apresentada neste trabalho a análise teórica de uma antena de microfita sobre um substrato cônico. A análise utiliza o modelo de cavidades com paredes laterais magnéticas na determinação da frequência de ressonância e impedância de a teoria das funções diádicas de Green, juntamente com as expressões assintóticas das funções esféricas de Hankel do segundo tipo, na obtenção dos campos distantes radiados pela antena. São apresentados também exemplos de antenas, operando no modo fundamental TM 01 e obtidos resultados para a frequencia de ressonância , impedância de entrada e diagrama de radiação do campo radiado distante. 0:1e resultados para a freqUência de ressonância, impedância de entrada e diagrama de radiação do campo radiado di stante. entrada da antena, e, juntamente com as esféricas de Hank el dist.antes radiados
Abstract: A theoretical analysis of a microstrip antenna on a conical substrate is presented. The cavity model with magnetic side walls is used for the calculation of the antenna resonant frequency and input impedance and the dyadic Green's functions formulation, in conjunction with asymptotic expressions of spher i cal Hank el functions of second type, are used for the calculation of the radiated fields in the far field region of the antenna. Some antennas, operating in the TM 01 mode were chosen as examples and numerical results for the resonant frequency, input impedance and radiation pattern were obtained.
Mestrado
Mestre em Engenharia Elétrica
29
Perrier, Mélanie. "Aux confins d'une relation à l'autre". Paris 1, 2005. http://www.theses.fr/2005PA010639.
Testo completoAbstract (sommario):
À l'heure des dispositifs dits ({ participatifs ", la place de l'autre nous semble être aujourd'hui un enjeu fondamental pour l'artiste et l'expérience, l'efficience de l'œuvre d'art. Examinant le sens d'une intrusion d'autrui dans le processus créatif, nous redéfinirons le public de l'œuvre sous le concept de multitude. Dans son articulation de l'un à l'autre, cette multitude profilera l'horizon de l'en-commun et de la singularité, imbibé du Mitsein heideggerien et de la communauté de Jean-Luc Nancy. Orientée sur cette ouverture à autrui, nous verrons une nouvelle " économie participative des vies " se dessiner où il convient d'accueillir autrui comme " vie nue à potentialité libre" et d'envisager la pratique de l'artiste sous le paradigme de la coopération; là où ses décisions se partagent et son implication se mue en responsabilité. La performance et la vidéo nous conduiront à une autre conception du féminin, délesté de son rapport oppositionnel au masculin et imprégné des théories queer. Ne pas exposer du lien mais faire interagir de l'en-commun, tel sera notre trajectoire, à partir de laquelle nous développerons un vocabulaire théorique susceptible de délimiter une " Esthétique de l'interaction" propice aux confins d'une relation à l'autre à condenser de la multitude
30
PORTO, PIMENTA AMILCAR. "Modélisation numérique d'un sillage réactif confiné". Poitiers, 1993. http://www.theses.fr/1993POIT2349.
Testo completoAbstract (sommario):
Le sillage reactif cree par un obstacle de section triangulaire place dans un ecoulement de canal turbulent de premelange reactif est etudie numeriquement. La modelisation de la combustion turbulente repose sur un modele statistique base sur la resolution de l'equation d'evolution d'une variable c, caracteristique de l'avancement des reactions chimiques. Cette equation est modelisee suivant une hypothese de flammelette valide aux grands nombres de damkohler. Les termes de transport turbulents de quantite de mouvement sont obtenus grace a une modelisation de type k- a faible nombre de reynolds qui permet de prendre en compte l'interaction avec la paroi solide. Le flux turbulent de la variable d'avancement est obtenu quant a lui soit par une modelisation de type gradient, soit par la resolution d'une equation d'evolution pour cette quantite (modelisation au second ordre). Les resultats numeriques obtenus permettent une premiere comparaison avec les resultats experimentaux disponibles sur cette geometrie pour les deux types de fermeture
31
Correa, Mauricio. "Um estudo comparativo do comportamento das afiações conica e conica radial (racon) em brocas helicoidais de aço rapido". [s.n.], 1996. http://repositorio.unicamp.br/jspui/handle/REPOSIP/264210.
Testo completoAbstract (sommario):
Orientador: Olivio NovaskiDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica
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Resumo: O objetivo principal deste trabalho é estudar o comportamento das afiações Racon (cônica radial) e Cônica em brocas helicoidais de aço rápido e analisar a performance das mesmas, buscando correlacioná-Ias às suas características geométricas. Para esta finalidade, realizou-se ensaios com dois materiais de diferentes usinabilidade, o aço SAE 4340 e o aço SAE 1045 utilizando-se três diferentes velocidades de corte associadas a um avanço específico para cada material. Testaram-se as afiações, repetindo-se as condições de corte três vezes para cada ponto ensaiado, evitando-se dessa maneira, influências aleatórias inerentes aos ensaios e aumentando-se quantitativa e qualitativamente as amostragens obtidas. Através desses experimentos, monitorou-se o percurso de usinagem, os esforços de corte (momento torçor e força de avanço), a evolução do desgaste de flanco e o alargamento dos furos usinados. Com os resultados obtidos levantaram-se hipóteses para explicar o comportamento de vida da ferramenta e esforços de corte (momento torçor e força de avanço). Constatou-se a superioridade da afiação Racon em vida de ferramenta, quando aplicada ao aço SAE 4340 e vida equivalente à Cônica, quando aplicada ao aço SAE 1045. Já, os esforços de corte observados (momento torçor e força de avanço) para afiação Racon mostraram-se inferiores aos da afiação Cônica, para praticamente todos os casos à exceção da força de avanço para a terceira condição de usinagem no aço SAE 1045. A partir dessas considerações presume-se que o comportamento da afiação Racon tende a ser semelhante em performance em outras condições de usinagem para os materiais ensaiados e possivelmente também para outros materiais demonstrando sua evolução frente à afiação Cônica
Abstract: The main goal of this work is to study the behaving of Racon (radiused conventional point) and Conical (conventional) drill points in high speed stell twist drills and analyse their performance, trying to correlate them to their geometrical features. For this purpose, tests with two different machinability materiais, the SAE 4340 and SAE 1045 steeIs, were carried out by using three different cutting speeds associated to an specific feed for each material. The drill points were tested by repeating three times the cutting condictions to each point, avoiding the random influences inherent to them and increasing the obteined samples both in quality and quantity. Cutting length, cutting forces (torque and thrust force), flank wear evolution and widening of the machined holes were supervised through out these tests. Hipoteses to explain toollife behaving and cutting forces (torque and thrust force) were generated with the obtained results. It was verified the superiority of Racon drill point in tool life when the SAE 4340 stell was used. But cutting forces in Racon drill point were inferior when compared to the conventional one in almost all cases, except the thrust force to the third cutting condiction in SAE 1045 steel. Through all these considerations it's presumed that Racon drill point behaving tends to be similar in performance in other cutting condictions in the tested materiaIs and possibly in other materiaIs showing its evolution over the conventional drill point
Mestrado
Engenharia de Fabricação
Mestre em Engenharia Mecânica
32
Yahiaoui, Nora. "Les Confins occidentaux de la Maurétanie Césarienne". Phd thesis, Ecole pratique des hautes études - EPHE PARIS, 2003. http://tel.archives-ouvertes.fr/tel-00534329.
Testo completoAbstract (sommario):
Le sujet traite de l'occupation romaine des Confins Occidentaux de la Maurétanie Césarienne. Le territoire étant vaste, nous l'avons limité, d'est en ouest, de l'oued El Mellah à l'oued Moulouya, du nord au sud, du littoral à la noua praetentura (voie romaine extrême sud des territoires occupés). Les phases historiques étudiées sont : la période maurétanienne [XIIe siècle à +40] et la période provinciale romaine jusqu'à la conquête arabe [ dynastie des Idrissides +40 à +68]. Trois ensembles d'études ont structuré cette recherche : une étude des sites, une étude du matériel archéologique [inscriptions et objets], enfin une reconstitution historique de l'occupation militaire, civile et religieuse des confins occidentaux de la Maurétanie Césarienne. La première étape indispensable à mon sens fut l'étude géographique des territoires concernés, en vue d'une reconstitution de la géographie antique. Pour cela nous commençons par localiser et identifier tous les sites antiques de ces confins de la Césarienne. La géographie de Ptolémée et l'Itinéraire d'Antonin sont les premières données que nous traitons. Elles sont suivies des informations laissées par les auteurs arabes du moyen âge, dont les deux principaux sont El Bekri et Al Hassan al Wazzân dit Léon l'Africain. Cela ne va pas sans une étude toponymique des sites, basée sur les données des auteurs antiques et des auteurs arabes, visant à comprendre le mode d'occupation romain : militaire et urbain. Nous constatons que ces toponymes sont plus souvent d'origine romaine que d'origine africaine, ce qui révèle le premier mode de l'occupation romaine, à savoir militaire. Cette localisation des sites est suivie d'une étude proprement géographique : géomorphologie, hydrologie, climat et conséquences sur la flore et la faune. La restitution géographique repose également sur les informations des auteurs anciens (grecs et latins) et des auteurs arabes. Nous en venons à une première partie de l'étude historique de ces confins césariens : la période maurétanienne, avec l'étude de la population autochtone ; suivie de la phase de l'occupation militaire romaine. La localisation des tribus est possible à partir des informations laissées en grande partie par Ptolémée, puis d'autres auteurs grecs et latins, enfin par les auteurs arabes du moyen âge dont Ibn Khaldoun. C'est donc à partir de ces données qu'il est possible de dresser une carte des tribus maures (sous réserve de nouvelles donnes). Il s'ensuit une chronique de la période maure, allant de la période libyco-punique à la royauté maurétanienne, jusqu'à l'arrivée des Romains ; enfin les différentes révoltes africaines en réponse à cette occupation romaine. Avec cet ensemble d'informations nous sommes plus disposés à comprendre les témoignages visibles : l'étude archéologique des sites que nous avons répartis en deux groupes selon leur position géographique. Les sites des territoires du littoral sont : Mersa Ben Mehidi [Lemnis ?], Tabarit, Ghazaouet [Ad Fratres], Honaïne [Gypsaria / Artisiga], Rachgoun et Takembrit [Portus Sigensis et Siga], Camérata [Camarata], Aïn Temouchent [Albulae]. Les sites des territoires intérieurs sont : Aïn el Hammam [Tepidae], Damous [Calama ?], Ouled Mimoun [Altava], Tlemcen [Pomaria], Maghnia [Numerus Syrorum], Aïn Reggada. L'étude de chaque site comprend un historique des recherches, les différentes publications, les témoignages des anciens, la position topographique du site, les vestiges visibles, les vestiges probables, les environs du site enfin la chronologie historique du site ; tout cela variant en fonction des données acquises. Le matériel archéologique dont nous avons fait usage pour cette thèse est composé de : - Quatre-vingt seize inscriptions de toutes celles qui furent inventoriées dans le Corpus Inscriptionum Latinarum, dans l'Année Epigraphique et dans divers articles spécifiques. Nous avons considérés toutes les inscriptions pourvues d'un intérêt historique. Elles sont de cinq natures : politiques, civiles, religieuses, funéraires et militaires. Les sites pour lesquels il fut possible de regrouper de tels documents sont : - Albulae et sa région [23 inscriptions allant, pour celles qui sont datables, de 117/118 à 501], - Siga [2 inscriptions, l'une civile datée entre 218 et 222 et une militaire non datée], - Altava et sa région [39 inscriptions allant, pour celles qui sont datables, de 201/209 à 529], - Pomaria et sa région [12 inscriptions allant, pour celles qui sont datables, de 217/218 au IIIe siècle], - Numerus Syrorum [17 inscriptions allant, pour celles qui sont datables, de 217/218 à 402]. Toutes ces inscriptions sont un support d'étude nous permettant d'analyser le présence humaine des confins occidentaux de la Maurétanie Césarienne, à savoir les différentes occupations romaines, ou influences, dans le cadre militaire, civil et religieux. - Le matériel archéologique en général. Il est davantage le résultat de découvertes fortuites que celui de réelles fouilles. Seule Siga connu de telles investigations. C'est dans ce site que fut découvert le plus grand nombre d'objets remontant à l'époque punique. Quatre catégories d'objets : les céramiques, les lampes, les pierres et marbres, puis les divers : - Siga [le matériel est très important : céramiques, lampes, pierres et divers autres objets pour la plupart découverts dans la nécropole romaine], - Albulae [céramique, lampes, marbres, pierres, bronzes et fer ; les endroits exacts et les conditions de découverte sont souvent inconnus], - Altava [céramique, lampes, pierres, métal, bronzes, argent, fers ; une bonne partie du matériel fut découvert dans les deux nécropoles d'Altava], - Pomaria [une céramique, une lampe, et un cadran solaire], Aïn Reggada [une table d'autel paléochrétien]. Le traitement des données des, différents sites, documents, inscriptions et matériels archéologiques, qu'il me fut possible d'amasser, permet d'établir une reconstitution de l'histoire antique de l'ensemble des confins occidentaux de la Maurétanie Césarienne. L'occupation militaire de ces confins fut la première approche physique des Romains. La question qui se pose alors est de savoir si l'intention première des Romains était une simple exploitation ou une implantation durable. Cette occupation militaire est matérialisée par des postes militaires [Altava, Pomaria, Numerus Syrorum, Aïn Khial, Albulae] recouvrant le territoire de manière à occuper tous le points stratégiques. Les voies romaines sont des impératifs d'organisation stratégique militaire, des obligations d'approvisionnement et des nécessités économiques pour le drainage des marchandises. L'étude de ces voies s'établi à partir des bornes milliaires, des témoignages antiques et témoignages des auteurs arabes. Ces voies recouvrent tout l'espace, du nord au sud [la Noua praetentura limite le sud] et d'est en ouest [la voie de Numerus Syrorum / Siga étant la dernière voie officielle à notre stade de connaissance]. Nous soulevons également le problème de ralliement entre les confins extrêmes ouest de la Césarienne et les confins extrêmes est de la Tingitane. Ce chapitre prend fin avec deux grandes interrogations : le retrait des troupes romaines à la fin du IIIe siècle met-il fin à l'Afrique romaine ? De quelle manière s'est fait le retour de la domination romaine au lendemain du passage des Vandales ? Dans un second temps nous abordons l'organisation civile, en commençant par les structures institutionnelles : la Maurétanie Césarienne, province impériale, le statut administratif des sites de ces confins [du cantonnement militaire au rang de "cité romaine"] ; les structures fiscales et commerciales : l'urbanisme, la ville, le mode fiscale et ses ressources, le monde rural et les exploitations des ressources.
33
Ovarlez, Guillaume. "Statique et rhéologie d'un milieu granulaire confiné". Phd thesis, Université Paris Sud - Paris XI, 2002. http://tel.archives-ouvertes.fr/tel-00001963.
Testo completoAbstract (sommario):
Un matériau granulaire confiné dans une colonne s'appuie sur les parois de celle-ci pour s'opposer aux forces extérieures qu'il subit. Il en résulte un couplage entre propriétés mécaniques du matériau et propriétés de surface de la colonne. L'étude de ce couplage constitue l'objet de cette thèse. Dans une première expérience, nous avons étudié le poids exercé par un milieu granulaire constitué de billes à la base d'une colonne. Nous avons défini une procédure expérimentale telle que le matériau est au seuil de glissement en tout point aux parois. Le poids mesuré sature avec la hauteur de billes ; la masse de saturation se met à l'échelle avec le rayon au cube, et diminue lorsque la densité et la friction aux parois augmentent. Lorsqu'on ajoute un surpoids à la surface supérieure du milieu granulaire, on observe un maximum, suivi d'une lente décroissance de la masse pesée en fonction de la masse versée. Ce maximum est plus élevé lorsque la densité et la friction aux parois augmentent. Les résultats obtenus sont comparés à différentes théories mécaniques des matériaux granulaires. Le modèle de Janssen décrit parfaitement le matériau granulaire non contraint par un surpoids. Mais l'ajout d'un surpoids met en défaut ce modèle, ainsi que le modèle OSL et l'élasticité homogène isotrope, même si cette dernière reproduit qualitativement tous les phénomènes observés. Dans une deuxième expérience, nous avons poussé la colonne granulaire vers le haut. La force de résistance à la poussée croît alors exponentiellement avec la hauteur de billes, ce que nous expliquons par le modèle de Janssen adapté à la poussée. A basse vitesse, nous observons un mouvement de « stick-slip », caractérisé par une force maximale de résistance à la poussée avant glissement qui croît fortement lorsque la vitesse décroît et lorsque l'humidité augmente. Nous expliquons ce phénomène par un vieillissement de la friction statique aux parois. A haute vitesse, nous observons une transition hystérétique vers un régime de glissement continu caractérisé par une force de résistance qui croît avec la vitesse et le taux d'humidité. Les phénomènes observés sont différents lorsqu'on change le matériau de la colonne, ce qui prouve l'influence primordiale des parois sur les effets observés. La mesure directe du coefficient de friction bille-paroi permet de retrouver les phénomènes observés. La poussée d'un système de billes de verre polydisperses dans une colonne en PMMA révèle un stick-slip régulier à très basse vitesse, qui devient irrégulier à plus haute vitesse, la distribution des glissements s'élargissant vers les petites valeurs.
34
Joma, Sameer. "Couplage galvanique Cu-Al en milieu confiné". Phd thesis, Université Pierre et Marie Curie - Paris VI, 2013. http://tel.archives-ouvertes.fr/tel-00831650.
Testo completoAbstract (sommario):
Les alliages aluminium-cuivre, et en particulier l'alliage 2024 (4% de Cu) sont utilisés dans l'industrie aéronautique pour leur faible densité alliée à de très bonnes propriétés mécaniques. Néanmoins, ces alliages sont très sensibles à la corrosion. Ainsi dans le cas de l'alliage 2024, la présence de précipités riches en cuivre, noyés dans une matrice d'aluminium, soumet cet alliage à un risque de corrosion galvanique. Dans une solution en plein bain contenant un électrolyte aéré de pH neutre, le couplage galvanique entre les deux métaux se produit comme prévu : la dissolution d'aluminium est la réaction anodique et la réduction de l'oxygène est la réaction cathodique à la surface du cuivre. La formation d'une crevasse à l'interface Al / Cu, avec re-déposition de cuivre dans le voisinage de l'interface a souvent été observée, mais n'a jamais été clairement expliquée. Ainsi, le but de ce travail est de mettre en évidence le mécanisme de dissolution du cuivre et de voir l'influence du confinement sur ce comportement. Un montage en couche mince a été mis au point au laboratoire, permettant d'obtenir une couche d'électrolyte (d'épaisseur inférieure à quelques centaines de micromètres) entre deux plans parallèles contenant respectivement des électrodes en cuivre pur et en aluminium pur. Le courant et le potentiel galvaniques ont été suivis en fonction du temps, de la distance entre les deux métaux, ainsi que du rapport des surfaces variant entre 10 et 0,1 entre le cuivre et l'aluminium. Après le remplacement de l'électrode supérieure par une paroi isolante, le comportement de l'électrode de cuivre a été suivi en présence d'ions Al3+ dans la couche mince. Enfin, le mécanisme de couplage galvanique est discuté en tenant compte de la modification du pH au sein de la couche mince d'électrolyte.
35
Weiss, Karine. "Gestion des relations interpersonnelles en milieu confiné". Paris 5, 1999. http://www.theses.fr/1999PA05H028.
Testo completoAbstract (sommario):
Les situations d'isolement et de confinement reflètent l'interaction complexe entre de nombreuses variables, et en particulier physiques et sociales, les sujets subissant d'une part l'isolement par rapport au monde habituel, et d'autre part la promiscuité à travers la présence continue d'autrui. Par conséquent, les comportements relationnels sont susceptibles de révéler un certain nombre de réactions liées à l'adaptation à ce type de situation. Afin d'identifier ces effets des contraintes situationnelles sur les comportements affiliatifs, une observation systématique a été effectuée, d'une part pendant un hivernage en antarctique, et d'autre part au cours d'une expérience de simulation des effets de l'apesanteur, ayant nécessité l'alitement continu de huit sujets pendant 42 jours (ESA/CNES). Dans les deux cas, l'observation des comportements a été complétée par des relevés permettant de connaitre la perception de la situation par les sujets (journal de bord, questionnaire). La première situation a permis d'étudier la formation des groupes d'affinités et leur évolution tout au long de la période d'isolement. Avec la seconde recherche, dans laquelle quatre dyades de sujets ont été préétablies, l'importance des relations a été mise en évidence par une régulation interpersonnelle à travers un effet de + contagion comportementale, s'exprimant par des styles comportementaux communs aux sujets partageant une chambre. Cette contagion, ainsi qu'une + évaluation relative ; de la situation marquent l'importance de la comparaison sociale, émotionnelle et instrumentale, au sein de chaque dyade. Dans les deux cas, l'étude de l'évolution des comportements et des évaluations permet de définir d'une part une phase d'apprentissage face à la nouveauté de la situation, et d'autre part un moment critique qui apparait aux trois-quarts de la période d'isolementIsolation and confinement are linked to a complex interaction between many factors, and especially physical and social ones. Subjects have to cope with social and physical isolation from their usual world. In the same time, they must face the promiscuity through the continue presence of others. Consequently, relational behaviours can reveal adaptation reactions in this kind of situation. A systematic observation has been made in two confined environments in order to identify these affiliative effects: on one hand during an antarctic wintering over, and on the other hand during an ESA/CNES experiment of weightlessness simulation. In this last one, eight subjects had to stay during 42 days in bed, in a head-down tilt position. In the two cases, the observation of interpersonal behaviours has been completed by verbal indicators of the situation's perception by the subjects (diary, questionnaires). The first situation allowed to study the construction of affiliative groups and their evolution during the isolation period. With the second research, in which dyads were artificially constituted before the beginning of the experiment, the importance of social relationships can be seen with an interpersonal regulation through an effect of "behavioural contagion", expressed by a common behavioural style in each dyad. This contagion, as well as a "relative evaluation" of the situation show the importance of the emotional or goal-oriented social comparison. In the two cases, it was possible to define on one hand a learning stage during which subjects could cope with the unusual situation, and on the other hand a negative stage corresponding to the "third-quarter phenomenon"
36
Rampisela, Petrus Fadjarbhakti. "Etude expérimentale de l'ébullition en espace confiné". Grenoble INPG, 1993. http://www.theses.fr/1993INPG0048.
Testo completoAbstract (sommario):
Dans divers procedes industriels, la miniaturisation fait que les problemes de refroidissement sont tres importants. Il faut extraire la chaleur a travers de petites surfaces. Les densites de flux de chaleur a extraire sont alors tres importantes et peuvent depasser celles qui sont obtenues avec des moyens classiques de refroidissement. Une possibilite de resoudre ce probleme consiste a ameliorer des phenomenes de transfert par ebullition par l'utilisation d'un espace confine. La construction d'un dispositif experimental a permis d'etudier, en ebullition en vase dans un espace confine cree entre deux plaques rectangulaires, les parametres suivants: la densite de flux de chaleur, le confinement, la condition peripherique et l'orientation. Deux correlations sont proposees pour calculer les coefficients d'echange moyen et local. Ces correlations sont fonction de nombres adimensionnels dont un, la fraction ouverte de la peripherie totale tenant compte de l'ecoulement de vapeur par les cotes, est nouveau
37
Le, Guer Yves. "Jet confiné, dispersions fluide-particules et mélange chaotique". Habilitation à diriger des recherches, Université de Pau et des Pays de l'Adour, 2005. http://tel.archives-ouvertes.fr/tel-00403912.
Testo completoAbstract (sommario):
Les travaux présentés concernent l'étude d'écoulements hydrodynamiques en situations complexes : écoulements instables, en régime d'advection chaotique ou encore multiphasique. Les phénomènes de transport et de transfert associés à ces écoulements sont étudiés (couplages instabilité-changement de phase, diffusif-réactif). Les applications sont nombreuses et se trouvent dans le domaine du génie des procédés.Les méthodes d'investigations sont essentiellement expérimentales, quelques développements numériques sont aussi présentés.
Le premier thème a trait à l'étude du comportement oscillatoire d'un jet fluide, plan, qui débouche dans une cavité contenant un obstacle. L'instabilité globale de l'écoulement conduit à son oscillation auto-entretenue. La dynamique du jet présente alors une fréquence caractéristique bien précise, dépendant principalement de paramètres géométriques, qui a permis d'envisager son utilisation comme débitmètre.
Le second thème abordé concerne l'étude de dispersions de particules flottantes en écoulement. Les deux projets présentés s'inscrivent dans le cadre plus général de l'étude de nouveaux fluides frigoporteurs diphasiques développés au LaTEP (les coulis de glace). Le premier projet se rapporte à une configuration académique : l'ascension d'une sphère de glace en colonne liquide. Les couplages dynamique (instabilités de sillage, trajectoires) et thermique (changement de phase) sont complexes, le régime d'écoulement évoluant à chaque instant. Le second projet de ce thème se rapporte à l'hydrodynamique d'une dispersion solide-liquide modèle en conduite cylindrique horizontale. Différents régimes d'écoulement non homogène ont été mis en évidence à partir de l'évolution spatio-temporelle du champ de vitesse, en fonction de la fraction solide de la phase dispersée.
Le troisième thème concerne l'étude du mélange obtenu en régime d'advection chaotique pour un écoulement laminaire. Plusieurs volets ont été développés autour de l'écoulement de Dean alterné tridimensionnel existant au sein de conduites courbes. Expérimentalement, il a été prouvé, par comparaison à un écoulement se développant dans un serpentin hélicoïdal, que les écoulements chaotiques sont plus efficaces en terme de mélange diffusif et réactif, donc jusqu'à une échelle moléculaire. Numériquement, une méthode originale basée sur la transformation de maillages anisotropes associés aux déplacements de scalaires advectés par l'écoulement a été mise au point. Elle permet l'évaluation, la comparaison et l'optimisation du mélange au sein d'écoulements 2D périodiques en temps ou 3D spatialement périodiques. Les efficacités d'écoulements régulier, partiellement chaotique et globalement chaotique sont analysées à partir de différents critères pour quantifier le mélange diffusif et réactif.
Aujourd'hui, de nouvelles applications du mélange chaotique sont considérées. Plus particulièrement, la production d'émulsions pétrolières à partir d'huiles lourdes très visqueuses est étudiée.
38
Ellis, Amanda. "Classification of conics in the tropical projective plane /". Diss., CLICK HERE for online access, 2005. http://contentdm.lib.byu.edu/ETD/image/etd1104.pdf.
Testo completo
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ASSENZA, SILVIA. "IL CONFINE NELLA LETTERATURA: LA SICILIA E TRIESTE". Doctoral thesis, Università Cattolica del Sacro Cuore, 2009. http://hdl.handle.net/10280/635.
Testo completoAbstract (sommario):
A partire dall’analisi dei concetti di ‘confine’ e di ‘frontiera’, lo studio indaga la letteratura siciliana e quella triestina, letterature nate su due terre liminali.
La tesi si compone di tre parti: la prima parte riguarda la letteratura siciliana; la seconda la letteratura triestina; la terza tenta un possibile confronto tra le due letterature. Per quanto concerne la letteratura siciliana gli autori e le opere studiate sono: Le città del mondo di Elio Vittorini, l’Horcynus orca di Stefano D’Arrigo in cui tutta la vicenda è concentrata sullo stretto di Messina, tra Scilla e Cariddi, ed un capitolo sulla lingua di Leonardo Sciascia, chiara espressione della circolarità dell’isola.
Per il versante triestino, nella seconda parte, gli autori e le opere studiate per il loro essere espressione della frontiera sono: Carlo Michelstaedter, La persuasione e la retorica ; Il capitano di lungo corso di Roberto Bazlen e infine Il richiamo di Alma Stelio di Mattioni che, come nel caso di Vittorini, traccia la mappa topografica di Trieste e si confronta con l’alterità.Beginning from the concept of ‘border’ and ‘frontier’, work investigates sicilian letterature and Trieste’s one, both born on the two boundering’s lands. Thesis is made of three parts: the first part concerns with Sicilian letterature; the second part about Trieste’s letterature. The third one tries a possible comparison between the two letteratures. About Sicilian letterature the autors and the studied works are: Le città del mondo by Elio Vittorini, The Horcynus orca by Stefano D’Arrigo where all the plot is set in the Straits of Messina, between Scilla and Cariddi, and a chapter about Leonardo Sciascia’s language, clear expression of island’s circularity. About triestin letterature, on the second part, autors and studied works, because of their being expression of the frontier, are: Carlo Michelstaedter, La persuasione e la retorica ; Il capitano di lungo corso by Roberto Bazlen and eventually Il richiamo di Alma by Stelio Mattioni which, as Vittorini, draws the topographic map of Trieste and compares itself with alterity.
40
Moutairou, Manani. "Application de réseaux Mesh dans un milieu confiné". Thesis, Université Laval, 2009. http://www.theses.ulaval.ca/2009/26388/26388.pdf.
Testo completoAbstract (sommario):
Cette thèse aborde le problème d’optimisation du déploiement des réseaux sans fil Mesh (Wireless Mesh Network) pour des applications large bande en milieu souterrain. Le déploiement des éléments du réseau a nécessité des études expérimentale et analytique du milieu.
L’étude expérimentale nous a permis de mieux cerner la topologie du milieu, de modéliser statistiquement le signal reçu et, surtout, d’étudier la couverture radio des éléments du réseau en fonction de leur localisation dans le milieu. Aussi, du point de vue réseau, certains comportements des réseaux à sauts multiples et à plusieurs interfaces radio ont été abordés. Il s’agit, par exemple, du problème de la limitation de la capacité globale du réseau engendrée par le nombre important de relais que subissent les paquets dans le réseau.
L’étude analytique quant à elle nous a permis de proposer trois approches de déploiement du réseau en milieu souterrain. Les différentes approches topologiques se distinguent selon qu’elles apportent au réseau une performance importante, une robustesse ou, finalement, une réduction globale du coût de déploiement.
Une première approche topologique consiste à trouver la ou les positions idéales de la passerelle qui permettent de réduire l’étranglement du réseau WMN en période de trafic très dense. Dans un milieu confiné, la topologie du réseau est étroitement liée à la configuration géométrique du milieu et, on peut aisément comprendre, le fait que certains liens du réseau sur utilisés (dépendamment du protocole de routage adopté) puissent compromettre la performance globale du réseau. Avec une telle configuration, tous les nœuds voisins achemineront le trafic à travers les mêmes liens sans fil dont les capacités sont bien sûr limitées.
La seconde approche topologique gère le problème de positionnement d’une passerelle de manière locale par formation de clusters (regroupements) indépendants. Elle nécessite des études préalables sur le comportement du réseau dans le milieu de déploiement. Ces études permettront de déterminer le dimensionnement de l’arbre qu'il convient de déployer pour la mise en place du réseau par regroupement arborescent (cluster) des éléments du réseau dans le milieu. Le dimensionnement de l’arbre recouvrant le sous-réseau tient étroitement compte de la densité du trafic dans celui-ci.
Cette seconde approche vient diminuer voire même résoudre le problème de congestion que peut poser l’approche initiale. Ce faisant, la taille de chaque cluster est rigoureusement dimensionnée de manière à autoriser une disponibilité conséquente de ressources quelque soit la position des usagers dans le réseau. Elle répond également à cette flexibilité tant recherchée en milieu souterrain de pouvoir déployer le réseau seulement à l’endroit où le besoin se fait sentir. Cette flexibilité qu’offre le réseau permet, par-dessus tout, aux industries minières de faire d’énormes économies en matière d’achats d’équipements de réseau.
Notre apport le plus significatif se situe au niveau de la performance de l’algorithme ‘Competitive Greedy’(CG)’ mis de l’avant pour gérer le réseau selon cette deuxième approche de positionnement de passerelles .Bien que la ‘Competitive Greedy’ soit légèrement plus gourmande en temps calcul que certains algorithmes existant dans la littérature, elle offre la meilleure solution en ce qui concerne le coût global du réseau (des solutions optimales qui permettent de réduire le coût du réseau). Ces performances seront minutieusement présentées et cet algorithme tient compte de la topologie du réseau, permet de gérer la taille du cluster, le nombre de relais que peut supporter chaque élément du réseau et, enfin, le nombre maximal de sauts (profondeur du réseau) qui séparent un élément quelconque du cluster à l’élément central du réseau qui est la passerelle.
La troisième approche topologique est légèrement plus chère que les deux premières approches à cause du nombre de passerelles qu’il faut déployer pour assurer la robustesse du réseau WMN. Elle vient surtout corriger une vulnérabilité du réseau qui réside dans la manière dont les passerelles sont déployées selon les deux approches précédentes. En effet, il peut arriver que le réseau soit exposé à différentes pannes et à d’éventuels accidents dans le milieu qui pourraient mettre en danger la sécurité de ses usagers.This thesis focuses on an optimization problem of the deployment of Wireless Mesh Network in an underground mine environment. The deployment of the network’s devices required analytical and experimental studies of the mining area. The experimental study allowed us to better define the topology of the area, to model the received signal power with statistics and especially to study the radio coverage of the network’s elements according to their location in the mine. Moreover, multihop and multiradio wireless mesh networks’ behaviour in the area is also addressed. To elaborate, the problem of the limitation of the total available capacity is due to the number of relays (hops) the packets are subjected to in the network. In regards to the analytical study, three approaches of the network deployment in the underground area were proposed. These different topological approaches bring different results in the network depending on the performance, the robustness and the total reduction of expenses. The first topological approach consists in finding one or several optimal positions of the gateway which allows us to reduce the congestion of the WMN network in very dense traffic periods. In a confined area, the topology of the network is closely linked to the geometric shape of the area due to overused established links (based on the adopted routing protocol) that compromise the total performance of the network. The second topological approach manages the problem of position of a gateway in a local way by forming tree based independent clusters. It requires prior studies on the behaviour of the network in the deployed area. These studies will allow us to determine the size of the tree that is necessary to unfold the installation of the network by clustering the elements of the network in the area. The size of the sub-network tree will closely take into account the traffic density in the area. This second approach reduces, and even resolves the problem of congestion that can occur in the first approach. Each cluster is strictly sized in such a way that it allows the disposal of a minimum resource at the level of users in the network whatever their positions are. It also answers the question of flexibility looked after in the underground area that will allow us to unfold network only in the location where needed. This flexibility of the network allows mining industries to make huge savings while purchasing network equipments. The most significant concept introduced is the algorithm “Competitive Greedy (CG)” that allows us to manage this network approach. Competitive Greedy algorithm requires more work than existing ones, but it does offer the best solution regarding the total cost of the network (optimum resolutions which allow us to reduce network expenses). These performances will thoroughly be introduced and this algorithm will allow us to manage the size of the cluster, the numbers of relays that each element of the network can support, and finally the maximum number of hops (network depth) which separates the clusters’ element with its associated gateway. The third topological approach is a little bit more expensive compared to the first two approaches because of the number of gateways required to assure the robustness of the WMN. It resolves vulnerability problem of the network in the way gateways are deployed according to the first two approaches. In fact, this third approach is very important as it is possible that the network can expose different failure and possible accidents in the environment that can cause severe security problem to the users.
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Minghini, Fabio. "Architetture di confine. Esperienze e progetti a confronto". Master's thesis, Alma Mater Studiorum - Università di Bologna, 2012. http://amslaurea.unibo.it/4297/.
Testo completo
42
Ellis, Amanda. "Classifcation of Conics in the Tropical Projective Plane". BYU ScholarsArchive, 2005. https://scholarsarchive.byu.edu/etd/697.
Testo completoAbstract (sommario):
This paper defines tropical projective space, TP^n, and the tropical general linear group TPGL(n). After discussing some simple examples of tropical polynomials and their hypersurfaces, a strategy is given for finding all conics in the tropical projective plane. The classification of conics and an analysis of the coefficient space corresponding to such conics is given.
43
Lovón, Cueva Marco Antonio. "Las palabras compuestas en el aimara de Conima". Pontificia Universidad Católica del Perú, 2019. http://hdl.handle.net/10757/626164.
Testo completoAbstract (sommario):
Dentro de los procesos de formación de palabras, el mecanismo morfológico de la composición ha sido poco estudiado en el aimara y en otras
lenguas andinas. Esta investigación muestra una descripción de las maneras
de cómo se conforman las palabras compuestas en la gramática del aimara
de Conima. Por tanto, en este trabajo se analizan la estructura y la combinatoria sintáctica de las palabras compuestas en esta variedad lingüística.
La data ha sido recogida de los hablantes y de la información procedente
de los principales diccionarios en aimara. En este estudio, se concluye que
el aimara de Conima forma compuestos a partir de seis patrones sintácticos
que siguen la estructura complemento-núcleo. Finalmente, en relación con
su tipología, en la indagación se indica que esta variedad emplea la composición para formar palabras compuestas básicamente de orden nominal.Within the processes of word formation, the morphological mechanism of the compounding has been little studied in Aymara and other Andean languages. This survey shows a description of the ways in which the compound words are formed in the grammar of Conima Aymara. Therefore, this work analyzes the structure and the syntactic combination of the composition in this linguistic variety. The data has been collected from the speakers and from the main dictionaries in Aymara. The present investigation concludes that the Conima Aymara forms compounds from six syntactic patterns that follow the complement-core structure. Finally, in relation to its typology, this survey points out that the Conima Aymara basically creates nominal compounding.
Revisón por pares
44
LEITE, LEONARDO DE SOUZA. "CONICS AND GRAPHS OF FUNCTIONS OF ONE VARIABLE". PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2015. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=26149@1.
Testo completoAbstract (sommario):
PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROCOORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
O objetivo deste trabalho é apresentar conteúdos necessários para a construção de uma base sólida em Matemática do Ensino Fundamental e Médio, mas que são em geral mal assimilados pelos alunos. Inicialmente apresentaremos o plano cartesiano, equações de uma e duas variáveis, funções de uma variável real e gráfico de funções. Passaremos então ao estudo de curvas simples e bem conhecidas dos alunos em geral, como a circunferência, e chegaremos até as cônicas rotacionadas. A partir daí, procuramos relacionar as duas partes do trabalho, mostrando como as cônicas podem ser vistas como gráficos de função de uma variável. Pretende-se que este trabalho possa ser utilizado por professores do Ensino Fundamental e Médio em sala de aula, pois boa parte do conteúdo apresentado faz parte do currículo mínimo da Secretaria de Educação do Estado do Rio de Janeiro. Propomos atividades teóricas e computacionais, utilizando o software Geogebra para construção de curvas no plano cartesiano.
The objective of this paper is to present content needed to build a solid foundation in mathematics from primary and secondary schools, but are generally poorly assimilated by the students. Initially present the Cartesian plane, equations of one and two variables, functions of a real variable and function graph. Then we pass to the study of simple curves and well known to students in general, as the circumference, and arrive until the conical rotated. From there, we try to relate the two parts of the work, showing how the taper can be seen as a variable function graphs. It is intended that this work can be used by teachers of primary and secondary education in the classroom, because much of the content presented is part of the minimum curriculum of the Department of Education of the State of Rio de Janeiro. We propose theoretical and computational activities, using the Geogebra software to build curves in the Cartesian plane.
45
Cheong, H. K. "Lateraly confine concrete prisms under various load conditions". Thesis, Imperial College London, 1985. http://hdl.handle.net/10044/1/37658.
Testo completo
46
He, Xuhua 1979. "Some subvarieties of the De Concini-Procesi compactification". Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/38452.
Testo completoAbstract (sommario):
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mathematics, 2005.Includes bibliographical references (p. 101-103).
This thesis is concerned with the intrinsic structure of the De Concini-Procesi compactification of semi-simple adjoint algebraic groups and some relations with other topics of algebraic groups. In chapter 1, we study the closure of the totally positive part of an adjoint group in the group compactification. One result that we obtain is the positive property of the closure with respect to the canonical basis. In addition, we get an explicit description of the closure. As a consequence of the explicit description, the closure admits a cellular decomposition, which was first conjectured by Lusztig. In chapter 2, we give a new proof of the parametrization of the totally positive part of ag variety which was first proved by Marsh and Rietsch using the generalized Chamber Ansatz. My proof is based on the theory of canonical basis. The remaining chapters are related to the pieces of the group compactification introduced by Lusztig in the paper "Parabolic character sheaves II". In chapter 3, we study the closure of the unipotent variety in the group compactification, following the previous work of Lusztig and Springer. We show that the closure of the unipotent variety is the union of the unipotent variety itself together with finitely many pieces. By the same method, we also prove a similar result for the closure of arbitrary Steinberg fiber. In chapter 4, we study the closure of any piece in the group compactification. We show that the closure is a union of some other pieces. We will also discuss the existence of cellular decomposition. Chapter 1, 3 and 4 of this thesis are roughly based on the papers [H1], [H2] and [H3], in that order. Chapter 2 is based on an unpublished result. Each chapter can be read independently of the others.
by Xuhua He.
Ph.D.
47
Granelli, Tommaso <1971>. "Negoziare confini: dagli stati di cose ai transiti". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2009. http://amsdottorato.unibo.it/2246/.
Testo completoAbstract (sommario):
Negotiating boundaries: from state of affairs to matter of transit. The research deals with the everyday management of spatial uncertainty, starting with the wider historical question of terrains vagues (a French term for wastelands, dismantled areas and peripheral city voids, or interstitial spaces) and focusing later on a particular case study. The choice intended to privilege a small place (a mouth of a lagoon which crosses a beach), with ordinary features, instead of the esthetical “vague terrains”, often witnessed through artistic media or architectural reflections. This place offered the chance to explore a particular dimension of indeterminacy, mostly related with a certain kind of phenomenal instability of its limits, the hybrid character of its cultural status (neither natural, nor artificial) and its crossover position as a transitional space, between different tendencies and activities. The first theoretical part of the research develops a semiotic of vagueness, by taking under exam the structuralist idea of relation, in order to approach an interpretive notion of continuity and indeterminacy. This exploration highlights the key feature of actantial network distribution, which provides a bridge with the second methodological parts, dedicated to a “tuning” of the tools for the analysis. This section establishes a dialogue with current social sciences (like Actor-Network Theory, Situated action and Distributed Cognition), in order to define some observational methods for the documentation of social practices, which could be comprised in a semiotic ethnography framework. The last part, finally, focuses on the mediation and negotiation by which human actors are interacting with the varying conditions of the chosen environment, looking at people’s movements through space, their embodied dealings with the boundaries and the use of spatial artefacts as framing infrastructure of the site.
48
Zannoni, Federico <1981>. "La città divisa. Conflittualità, confini, prove di comunità". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amsdottorato.unibo.it/5463/.
Testo completoAbstract (sommario):
Il presente lavoro approfondisce le tematiche della conflittualità e della separazione etnica, sociale, religiosa, generazionale e culturale. In particolare, riporta i risultati di ricerche condotte in alcuni degli attuali contesti urbani più carichi di tensioni conflittuali, cercando di individuare i motivi vicini e remoti del confligere, le attività messe in atto per contenere le tensioni e le relative necessità educative poste in primo piano.
L’elaborato si compone di cinque parti. La prima parte consiste in una riflessione teorica sulle dinamiche che caratterizzano le interazioni sociali nello spazio cittadino. Nella seconda parte viene trattato il tema del settarismo in Scozia, che vede contrapposti i cattolici di origine irlandese (generalmente tifosi della squadra di calcio dei Celtic) e i protestanti di sangue scozzese (generalmente tifosi dei Rangers). La terza parte ricostruisce la storia e il presente della lunga convivenza tra tatari musulmani e russi cristiano-ortodossi nei territori dell’attuale Repubblica etnica del Tatarstan, situata nel cuore della Russia europea, ponendo particolare attenzione agli aspetti religiosi, linguistici, culturali ed educativi. La quarta parte parla del disagio nelle periferie europee, manifestatosi in modo eclatante con le rivolte giovanili in Francia (2005) e nel Regno Unito (2011). La parte conclusiva, infine riprenderà alcuni degli elementi emersi per proporre una riflessione di tipo pedagogico atta ad affrontare in tutta la sua complessità, e con approcci nuovi, il tema della città divisa, con le relative conflittualità, i confini e le prove di comunità.This paper investigates the themes of conflict and separations in their ethnic, social, religious, generational and cultural dimensions. In particular, it reports the results of researches conducted in some of the most complex urban areas, trying to identify the reasons of the conflicts, the activities put in place to curb the strains and the educational needs placed in the foreground. The paper consists of five parts. The first part is a theoretical analysis on the dynamics that characterize the social interactions in the city space. The second part deals with the issue of sectarianism in Scotland, which sees opposing Catholics of Irish descent (usually supporters of Celtic football team) and the Protestants of Scottish blood (usually Rangers’ fans). The third part traces the history and the present of the coexistence between Muslim Tatars and Christian-Orthodox Russians in the ethnic Republic of Tatarstan, situated in the heart of European Russia, paying particular attention to the religious, linguistic, cultural and educational issues. The fourth part analyses the discomfort in the European peripheries, that has been manifested with the youth revolts in France (2005) and in the UK (2011). The final part resumes some of the issues in order to suggest a pedagogical reflection to face the theme of the divided cities.
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Leung, Hau Yan. "Aramid fibre spirals to confine concrete in compression". Thesis, University of Cambridge, 2000. https://www.repository.cam.ac.uk/handle/1810/272300.
Testo completo
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Guérin, Adrien. "Dynamique de l'écoulement dans un aquifère non confiné". Sorbonne Paris Cité, 2015. https://hal.science/tel-01884762.
Testo completoAbstract (sommario):
L'évolution du débit d'une rivière présente généralement des épisodes de crues intenses, au cours desquels le débit augmente rapidement, suivis par une diminution lente du débit lorsque la pluie s'arrête. Dans ce manuscrit, nous montrons que l'écoulement souterrain dans un aquifère non confiné permet de comprendre cette dynamique. Dans le cadre de l'approximation de Dupuit-Boussinesq (eau peu profonde), la vitesse de montée de crue ˙Q est une fonction non-linéaire du taux de précipitations R : ˙Q ∝ R 3/2. Après la pluie, on distingue deux régimes asymptotiques de décrue. Au début de la décrue, le débit décroît proportionnellement à l'inverse de la racine du temps ( Q ∝ 1/ √ t (Polubarinova-Kochina, 1962)). En fin de décrue, le débit décroît comme l'inverse du temps au carré (Q ∝ 1/t 2(Boussinesq, 1903)). L'étude d'un aquifère de laboratoire soumis à une pluie artificielle confirme l'existence de ces régimes asymptotiques. Ce dispositif expérimental simplifié (aquifère homogène et bidimensionnel) génère des montées de crue réalistes, en l'absence de ruissellement. L'instrumentation d'un site de terrain dans le bassin versant de la Ravine Quiock, sur l'île de Basse-Terre en Guadeloupe, révèle un comportement similaire. La surface de la nappe et le débit de la rivière évoluent simultanément pendant la pluie et se conforment aux prédictions théoriques. Comme dans l'expérience de laboratoire, cet aquifère réagit donc non-linéairement au forçage induit par les précipitations. L'analyse de données acquises dans trois autres bassins versants (Plynlimon, Pays de Galles, et Laval, France) confirme le caractère non-linéaire de la réponse d'un aquifère à la pluie : ˙Q ∝ Rn, avec n > 1. Cependant, l'exposant obtenu est différent de 3/2. Une expérience préliminaire en laboratoire suggère que cet écart à la théorie de Dupuit-Boussinesq pourrait être induit par l'écoulement vertical dans l'aquifèreRiver hydrographs generally exhibit intense flood events during which the discharge increases quickly during rainfall, anc decreases slowly afterwards. In this manuscript, we show that the dynamics of groundwater in an unconfined aquifer can account for these features. In the frame of the Dupuit-Boussinesq (shallow-water) approximation, the discharge increase rate ˙Q is a non-linear fonction of the rainfall rate R : ˙Q ∝ R 3/2. After the rain, two consecutive asymptotic regimes compose the drought flow. During the early drought flow, the discharge decreases as the inverse square root of time ( Q ∝ 1/ √ t(Polubarinova-Kochina (1962)). Later, the discharge decreases as the inverse square of time (Q ∝ 1/t 2(Boussinesq, 1903)). A laboratory aquifer (homogeneous and bidimensional) submitted to artificial rainfall confirms the existence of these asymptotic regimes. This simplified experimental setup generates a realistic flood signal, in the absence of surface runoff. Field observation in the catchment of the Quiock Creek, Guadeloiipe reveals a similar behaviour. The water table and the river discharge evolve simultaneously during rainfall, and conform to theory. Like in our laboratory experiment, this aquifer reacts non-linearly to forcing by rainfall. The river discharge from three other catchments (Plynlimon, Wales and Laval, France) confirms this non-linear reaction : ˙Q ∝ R n , with n > 1. The exponent, however, is different from 3/2. A preliminary laboratory experiment suggests that this breakdown of the Dupuit-Boussinesq theory is due to vertical groundwater flow