Дисертації з теми "Injection dynamics"
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1
Conley, Nancy Ann. "The dynamics of cavity pressure in thermoplastic injection molding /." Thesis, McGill University, 1985. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=65924.
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Hudgins, Duane Edward. "Suppression of premixed combustion dynamics utilizing microjet air injection." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/45213.
Повний текст джерелаАнотація:
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2008.Includes bibliographical references (leaves 119-123).
The problem of thermoacoustic instability in continuous combustion systems is a major challenge in the field of propulsion and power generation. With the current environmental and political pressure that is being placed on the consumption of fossil fuels, this subject has become even more critical. In the past, the presence of combustion instability could be avoided by designing a combustor with fixed inlet conditions, where these conditions were conducive to a stable system. Today, utilities and providers of propulsion systems are under pressure to make systems that are not only more efficient and clean, but also have a greater flexibility of input fuel. In order to accomplish this, combustion engineers need an even deeper insight into what causes thermoacoustic instability and they need a wider array of tools at their disposal to suppress these instabilities. This thesis adds pieces of that deeper insight and provides another tool to tackle this difficult problem. As a first step in the further understanding of thermoacoustic instabilities, experiments were done in a premixed gas backwards facing step combustor using propane or propane/hydrogen mixture as a fuel. I fully characterized the combustion dynamics in this combustor by measuring the four defining states of the system. These states are pressure, heat release, velocity, and equivalence ratio. Once these measurements were performed I tested two novel approaches to suppressing thermoacoustic instabilities through the use of microjet air injection. This was done by building upon a previous combustor setup to allow the installation of several new diagnostic capabilities and the new microjets.
(cont.) The new diagnostics include stand-off pressure sensors to measure pressure in the hot exhaust region, a hot wire anemometer to measure velocity, a photomultiplier tube to measure the integrated heat release, an automated gas probe to measure fuel concentration profiles, and a laser absorption sensor to measure the temporal variance in equivalence ratio. The novel microjets were built into the newly designed test section. By fully characterizing the system I was able to show how both equivalence ratio oscillations and wake vortex interactions drive the thermoacoustic instabilities of the combustion. I have also shown that the stability range shifts to leaner equivalence ratios as inlet temperature or hydrogen content in the fuel is increased. This thesis demonstrates the great potential the microjet air injection has for extending the range of stability of the system.
by Duane Edward Hudgins.
S.M.
3
Chlouverakis, Konstantinos E. "Theory of dynamics of semiconductor lasers subject to optical injection." Thesis, University of Essex, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.413642.
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Pina, Estany Jordi. "Micro and nanostructures replication via injection moulding." Doctoral thesis, Universitat Ramon Llull, 2018. http://hdl.handle.net/10803/663803.
Повний текст джерелаАнотація:
Des del descobriment del poliestirè i el PVC a principis del segle XX, els plàstics han revolucionat el nostre dia a dia. Les 250 milions de tones que es fabriquen cada any s'utilitzen en un ampli ventall d'aplicacions com l'embalatge, la construcció, el transport, la medicina, l'electrònica, etc.
D'una forma similar, es preveu que la nanotecnologia sigui una innovació disruptiva el segle XXI. Des que la nanotecnologia va néixer com a ciència als anys 80, han aparegut un ampli ventall d'aplicacions com els xips en laboratoris, les superfícies amb propietats d'autoneteja, les superfícies antimicrobianes, aplicacions òptiques, etc.
Actualment, la nanotecnologia està saltant des dels centres de recerca cap a la indústria. Per fer això, el plàstic sembla ser un material adequat gràcies al seu baix cost, la fàcil fabricació i les propietats interessants com l'alta resistència tot i el baix pes, la durabilitat, la resistència a la corrosió, la transparència, etc.
Aquesta tesi estudia en detall com l'injecció de plàstic es pot utilitzar per fabricar peces de plàstic amb àrees nanoestructurades. La dinàmica de fluids i la dinàmica molecular s'utilitzen per quantificar els paràmetres de procés i geomètrics que afecten la replicació. Des d'un punt de vista experimental i dins d'un marc de treball comú entre IQS (Universitat Ramon Llull), CSIC i Flubetech, s'injecta plàstic en motlles amb zones nanoestructurades i s'utilitza un microscopi de forces atòmiques per quantificar l'efecte en la replicació de la temperatura, el temps d'omplerta, la càrrega de polímer i la geometria de la nanocavitat. Per acabar, SEAT i l'IQS han unit esforços per desenvolupar una aplicació industrial centrada en la millora de l'homogeneïtat lumínica mitjançant el nanotexturitzat d'una superfície, s'ha obtingut d'aquesta manera un mètode més econòmic i eficient que els utilitzats actualment en l'il·luminació de fars i pilots.Desde el descubrimiento del poliestireno y el PVC a principios del siglo XX, los plásticos han revolucionado nuestro día a día. Las 250 millones de toneladas que se fabrican cada año se utilizan en un ámplio abanico de aplicaciones como los embalajes, la construcción, los transportes, la medicina, la electrónica, etc. De una forma parecida, se prevé que la llegada de la nanotecnología sea un cambio disruptivo del siglo XXI. Desde que la nanotecnología nació como ciencia en los años 80, han aparecido distintas aplicaciones en distintos sectores como los laboratorios en chips, las superfícies autolimpiantes, las superfícies antimicrobios, aplicaciones ópticas, etc. Actualmente, la nanotecnología está saltando desde los centros de investigación a la industria. Para conseguir este salto, el plástico parece ser un material adecuado debido a su bajo coste, fácil fabricación y propiedades interesantes como su alta resistencia aún y su bajo peso, la resistencia a la corrosión, la transparencia, etc. Esta tesis estudia en detalle como la inyección de plástico se puede usar para fabricar piezas de plástico con zonas nanoestructuradas. La dinámica de fluidos computacional y la dinámica molecular se utilizan para cuantificar los parámetros de proceso y geométricos que afectan a la replicación. Desde el punto de vista experimental y en un trabajo conjunto entre IQS (Universidad Ramon Llull), CSIC y Flubetech, se inyecta plástico en moldes con superfícies nanoestructuradas y se analiza con un microscopio de fuerzas atómica el efecto en la replicación de la temperatura, el tiempo de llenado, la carga de polímero y la geometría de la nanocavidad. Para acabar, SEAT y IQS han unido esfuerzos para desarrollar una aplicación industrial centrada en la mejora de la homogeneidad lumínica mediante el nanotexturizado de una superficie, obteniendo así un método más económico y más eficiente que los métodos usados actualmente en iluminación de faros o pilotos.
Since polystyrene and PVC were discovered at the beginning of the 20th century, plastics have revolutionized our daily lives. The 250 millions of tonnes that are manufactured each year are used in a wide field of applications like packaging, building and construction, transportation, medical, electronics, etc. In a similar way, nanotechnology is called to lead a disruptive change on the 21th century. Since nanotechnology emerged as a science in the 1980s, a wide field of applications has appeared in different areas like lab-on-chips devices, surfaces with self-cleaning capabilities, antimicrobial surfaces, optical applications, etc. Currently, nanotechnology is jumping from the research area to the mass production industry. To do so, plastic appears to be a suitable material for its low cost, easiness to manufacture and interesting properties like high strength-to-weight ratio, durability, corrosion resistance, transparency, etc. This thesis studies in detail how injection moulding manufacturing technique can be used for manufacturing plastic parts with micro and nanostructured areas. Computational Fluid Dynamics and Molecular Dynamics simulation methods are used to quantify the process and geometrical factors that effect the replication. From the experimental point of view, in a common work between IQS (Ramon Llull University), CSIC and Flubetech, plastic is injected in moulds with nanostructured areas and an Atomic Force Microscope is used for quantifying the effect of temperature, filling time, polymer charge and nanoscale geometries in the replication of nanocavities. Finally, SEAT and IQS joined efforts to develop an industrial application consisting into an improve of light homogeneity through the nanotexturising of a surface, obtaining a costs reduction and a better efficiency than the currently used methods for lighting headlamps and rear lights.
5
Hohl, Angela. "Dynamics of semiconductor laser systems with optical injection and external feedback." Diss., Georgia Institute of Technology, 1995. http://hdl.handle.net/1853/29450.
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Gomes, Vincent G. (Vincent Gracias). "The dynamics and control of melt temperature in thermoplastic injection molding /." Thesis, McGill University, 1985. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=65921.
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Gao, Furong. "Measurement, dynamics and control of the mold temperature of injection molding." Thesis, McGill University, 1989. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=62000.
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Ye, Ming, Raziuddin Khaleel, and Tian-Chyi J. Yeh. "Stochastic analysis of moisture plume dynamics of a field injection experiment." Department of Hydrology and Water Resources, University of Arizona (Tucson, AZ), 2004. http://hdl.handle.net/10150/615750.
Повний текст джерелаАнотація:
A vadose zone field injection experiment was conducted in the summer of 2000 at theHanford Site, Washington. The unique moisture content database is used to identify the lithology at the field site and to interpret, visualize, and quantify the spatio- temporal evolution of the three -dimensional (3 -D) moisture plume created by the injection experiment. We conducted a hierarchical geostatistical analysis to examine the large -scale geologic structure for the entire field site, and then investigate small -scale features within different layers. Afterward, variogram analysis is applied to the O field measured for seven different days during the injection experiment. Temporal variations of sills and ranges are related to the observed moisture plume dynamics. A visualization of the 3 -D moisture plume evolution illustrates effects of media heterogeneity. Statistics of changes in moisture content as a function of distance reveals large variance near the wetting front and the coefficient of variation increases with decreasing mean.These findings support the gradient- and mean -dependent variability in the moisture content distribution as reported by existing stochastic theories. Spatial moment analysis is also conducted to quantify the rate and direction of movement of the plume mass center and its spatial spreading. The ratio of horizontal to vertical spreading at varying moisture contents suggests moisture- dependent anisotropy in effective unsaturated hydraulic conductivity, confirming existing stochastic theories. However, the principal directions of the spatial moments are found to vary as the moisture plume evolves through local heterogeneity, a feature that has not been recognized in the theories.
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Doumbia, Yaya. "Optical injection dynamics and polarization properties of semiconductor lasers frequency combs." Electronic Thesis or Diss., CentraleSupélec, 2021. http://www.theses.fr/2021CSUP0008.
Повний текст джерелаАнотація:
Dans ce travail, nous étudions la dynamique non linéaire de diodes laser injectées optiquement avec des peignes de fréquence.Nous analysons d'abord théoriquement et expérimentalement la dynamique non linéaire des lasers à émettant par la tranche (EELs) à partir d'une injection optique de peignes de fréquence. Les paramètres d'injection et les propriétés du peigne injecté sont variés pour dévoiler plusieurs dynamiques verrouillées et déverrouillées. Pour une force d'injection suffisamment grande et sur une large plage de désaccord, le verrouillage d'injection bifurque vers une dynamique temporelle correspondant à un peigne de fréquence optique qui étend le peigne injecté à un spectre optique beaucoup plus large. Une analyse de bifurcation révèle une dynamique de peigne de fréquence harmonique en cascade conduisant à une augmentation significative des lignes de peigne de sortie. Nous avons également utilisé les paramètres d'injection, les propriétés du peigne et le courant d'injection pour contrôler les propriétés du nouve peigne. Dans un deuxième temps, nous analysons expérimentalement la dynamique non linéaire et les propriétés de polarisation dans des lasers émettant par la surface (VCSEL) soumis à une injection optique orthogonale avec des peignes de fréquence. Plus important encore, le VCSEL montre deux peignes de fréquence avec une polarisation orthogonale à partir d'un seul appareil pour certains paramètres d'injection. Nous démontrons également la possibilité de contrôler le taux de répétition des peignes à une ou deux polarisations grâce à la génération de peignes à fréquence harmonique. Nous présentons enfin expérimentalement et théoriquement la dynamique d'injection de VCSEL à partir d'une injection de peigne de fréquence optique avec une polarisation parallèle à celle du VCSEL. Nous montrons que la performance des peignes à deux polarisations sont limitées à une injection de courant élevé dans le cas d'une injection optique parallèle. Pour un courant de polarisation fixe, la dynamique des deux peignes de polarisation disparaît lorsque l'on augmente l'espacement des peignes injectés.Cette thèse démontre donc outre son intérêt pour la dynamique laser non linéaire, l'injection optique est une technique permettant d'exploiter les propriétés de peigne dans les diodes laserIn this work, we study the nonlinear dynamics of laser diodes optically injected with frequency combs.We first theoretically and experimentally analyze the nonlinear dynamics of edge-emitting lasers (EELs) from an optical injection of frequency combs. The injection parameters and injected comb properties are varied to unveil several locked and unlocked dynamics. For large enough injection strength and over a large detuning range, the injection locking bifurcates to a time-periodic dynamics corresponding to an optical frequency comb that extends the injected comb to a much broader optical spectrum. A bifurcation analysis reveals a cascade harmonic frequency comb dynamics leading to a significant increase in the output comb lines. We have also used the injection parameters, comb properties, and injection current to control the new comb properties. We secondly analyze the nonlinear dynamics and polarization properties in vertical-cavity surface-emitting lasers (VCSELs) subject to orthogonal optical injection with frequency combs experimentally. Most importantly, the VCSEL shows two frequency combs with orthogonal polarization from a single device for some injection parameters. We also demonstrate the possibility to control the single or two polarizations comb repetition rate through harmonic frequency combs generation. We finally present experimentally and theoretically the VCSEL injection dynamics from parallel optical frequency comb injection. We show that the two polarizations combperformance is restricted to high current injection in the case of parallel optical injection. For fixed bias current, the two polarization comb dynamics disappear when increasing the injected comb spacing.This thesis therefore demonstrates besides its interest for nonlinear laser dynamics, optical injection is a technique to harness the comb properties in laser diodes
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Pastor, Diego Garcia. "The study of boundary layer control in a turbopump diffuser with fluid injection /." Online version of thesis, 1996. http://hdl.handle.net/1850/12290.
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11
Simoes, Ricardo J. F. "Mechanical behavior and performance of injection molded semi-crystalline polymers." Thesis, University of North Texas, 2003. https://digital.library.unt.edu/ark:/67531/metadc5528/.
Повний текст джерелаАнотація:
I have used computer simulations to investigate the behavior of polymeric materials at the molecular level. The simulations were performed using the molecular dynamics method with Lennard-Jones potentials defining the interactions between particles in the system.
Significant effort was put into the creation of realistic materials on the computer. For this purpose, an algorithm was developed based on the step-wise polymerization process. The resulting computer-generated materials (CGMs) exhibit several features of real materials, such as molecular weight distribution and presence of chain entanglements.
The effect of the addition of a liquid crystalline (LC) phase to the flexible matrix was also studied. The concentration and distribution of the second phase (2P) were found to influence the mechanical and tribological properties of the CGMs. The size of the 2P agglomerates was found to have negligible influence on the properties within the studied range. Moreover, although the 2P reinforcement increases the modulus, it favors crack formation and propagation. Regions of high LC concentration exhibit high probability of becoming part of the crack propagation path. Simulations of the tensile deformation under a uniaxial force have shown that the molecular deformation mechanisms developing in the material depend on several variables, such as the magnitude of the force, the force increase rate, and the level of orientation of the chains. Three-dimensional (3D) graphical visualization tools were developed for representation and analysis of the simulation results. These also present interesting educational possibilities. Computer simulations provide us information which is inaccessible experimentally. From the concomitant use of simulations and experiments, a better understanding of the molecular phenomena that take place during deformation of polymers has been established.
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Yoon, Sung Joon. "Numerical Navier-Stokes solutions of supersonic slot injection problems." Diss., Virginia Polytechnic Institute and State University, 1988. http://hdl.handle.net/10919/54473.
Повний текст джерелаАнотація:
Supersonic slot injection problems were studied by a finite volume method. The numerical technique used is the upwind method of Roe’s flux difference splitting (FDS) with vertical line Gauss-Seidel relaxation applied to the thin layer Navier-Stokes equations. To test the accuracy of the numerical methods without the complications and uncertainties of turbulence modeling, two sample cases were chosen with laminar flows. The sample problems were the compressible laminar boundary layer flow over a flat plate and the laminar boundary layer - shock interaction problem. For these problems, both the results from Roe’s FDS and van Leer’s flux vector splitting (FVS) are compared with exact solutions and experimental data. For the sample problems, comparisons showed that Roe’s FDS method is more accurate than van Leer’s FVS method. Because of the very complicated wave patterns and strong viscous-inviscid interaction produced by supersonic slot injection, an adaptive grid based on the equidistribution law was combined with the solution algorithm. The results from Roe’s FDS method with the adaptive grid showed good results for the supersonic slot injection over a flat plate. For the slot injection over a 10-degree wedge surface case, there is a significant difference between the numerical and experimental wall pressure distribution. Some potential reasons for the discrepancy including 3D effects and/or transition in the reattachment region in the experiments and possibly a need for a much finer grid in the calculations are discussed.Ph. D.
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Koksal, Murat. "Gas mixing and flow dynamics in circulating fluidized beds with secondary air injection." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/NQ63479.pdf.
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Gordon, R. "Investigating the ultra-fast dynamics of semiconductor lasers by optical pulse injection techniques." Thesis, University of Cambridge, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.599528.
Повний текст джерелаАнотація:
Resonant injection of sub-picosecond optical pulses were explored as an ultra-fast analogue to injection locking, to influence the phase of the semiconductor laser on short time-scales. This allowed for efficiently altering the absolute phase of the lasing modes (without exciting new modes to lase) and produced mode interference beating; both demonstrated in vertical cavity surface emitting lasers (VCSELs). The ultra-fast optical sampling was extended to resolve polarization degrees of freedom, showing the nonlinear coupling between transverse modes through the charge carriers. Phase-sensitive double-pulse injection, commonly used for coherent control, was applied to VCSELs to introduce a field component into a specifically selected subset of the transverse lasing modes. The self-organization between transverse modes in VCSELs was investigated with resonant pulse injection and optical sampling. At different bias currents, mode-locking was observed to produce both a train of 2 ps pulses with an 11 ps repetition period, and self-organization of the laser mode resonances to tones within the Fibonacci sequence (with a 19 GHz fundamental tone). It was demonstrated that the nonlinear optical sampling technique could be used to measure the coherence length and type of fluctuations within the VCSEL. While the pulsed mode-locking showed the expected shot-noise fluctuations from spontaneous emission, the Fibonacci-type mode-locking was more stable and showed popcorn noise. The emergence of the Fibonacci-type mode-locking was explained by a spatio-temporal theory of the symmetry-breaking interaction between nearly degenerate modes and the carrier density. Edge-emitting semiconductor laser structures, with and without an optical grating, were also investigated. Resonant and non-resonant optical pulses were used to free laser light from a trapped defect state within an optical grating, and create carrier-heating relaxation oscillations. These effects were reproduced with a spatio-temporal model. Double pulse injection was used to measure the separate effects of group-velocity dispersion and gain curvature on pulse propagation within a Fabry-Pérot laser.
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Cuppoletti, Daniel R. "Supersonic Jet Noise Reduction with Novel Fluidic Injection Techniques." University of Cincinnati / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1384333927.
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PAOLICELLI, FEDERICA. "Hydraulic circuit layout analysis, diagnostics and control of the injection process in Common Rail diesel fuel injection systems." Doctoral thesis, Politecnico di Torino, 2017. http://hdl.handle.net/11583/2690958.
Повний текст джерелаАнотація:
Current fuel injection systems should provide more and more reliable performance in management and control of the injection event, to improve the efficiency of the fuel combustion process and thus meet both environmental and consumer demands. Small fuel quantities are usually injected before the main injection to reduce the combustion noise. Whereas, small injections following the main shot are employed to optimize the combustion development and to reduce pollutant emissions. Since the number of shots in multiple injections has increased over the years, the injected amount of fuel for each shot has become smaller, given a fix total amount of fuel. The control of injected fuel quantities is therefore a demanding task and any failure causes a worse combustion process and higher pollutant emissions.
This study is focused on the modelling of Common Rail (CR) fuel injection systems for diesel applications and the implementation of specific mathematical techniques to examine phenomena pertaining to the fuel injection dynamics. New methodologies for detecting key events of the injection process and to estimate the injected fuel quantity have been developed for control purposes.
A 1D numerical model of a solenoid-actuated injector equipped with a pressure-balanced pilot-valve has internally been developed to evaluate the main hydraulic and mechanical quantities. The impact of a pressure-balanced and a standard pilot-valve layout has been investigated, and the performance of a standard CR system has been compared to that of a novel injection system concept, i.e., the Common Feeding (CF). A sensitivity analysis of the main design parameters of the pressure-balanced pilot-valve layout has been carried out, with the purpose of improving the general performance of the system.
A dedicated lumped parameter model of the high-pressure hydraulic circuit of the CR system has been used to calculate the natural frequencies and modes of vibration. It has been found that the direction and the magnitude of the fuel flow rates along each pipe of the apparatus can be derived from the first three modes (and the corresponding eigenvectors). The main objective is to identify which components could primarily be stressed for the main modes of vibration. Finally, external forcing terms acting on the system have been investigated to determine possible causes of hydraulic resonance.
The identification of specific events that characterize the injection process, such as pilot-valve and injector nozzle opening and closure phases, might play a significant role for diagnostics and control of the system in on-board and real-life applications. To this end, time-frequency analysis techniques have been used to detect key events of the injection process. The method has then been applied to several working conditions to test its robustness. Specifically, the pressure time-history acquired along the rail-to-injector pipe has been transformed from the time domain into the joint time-frequency domain, so that changes within the new signal would highlight the events to be detected.
Even though the diagnostics of injection events is an important topic, one of the main issues for injection systems is the absence of a closed-loop real-time control. The control unit should be able to evaluate the amount of fuel injected into the combustion chamber and eventually to correct it, based on the comparison with the target quantity stored in the engine maps. In this perspective, a quadratic correlation between the fuel amount that enters the injector and the injected fuel quantity has been found. The presented algorithm, which is specific for small injections, converts the pressure time-history acquired along the rail-to-injector pipe into an instantaneous fuel flow rate, calculates the fuel amount at the injector inlet by integration and the actual injected fuel quantity by means of the quadratic correlation. The entire process can be executed in real-time.
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Bierer, Andrew M. "Nitrogen dynamics and biological response to dairy manure application." Diss., Virginia Tech, 2019. http://hdl.handle.net/10919/90372.
Повний текст джерелаАнотація:
Animal manures are land applied in agronomic systems to supply essential crop nutrients and decrease dependency on chemical fertilizers. Liquid manures are traditionally surface broadcast to fields and sometimes incorporated to reduce odor and nutrient losses; however, incorporation is incompatible with no-till agriculture. Subsurface manure injection is a no-till compatible alternative application method which addresses these concerns, but likely changes the dynamics of nutrient cycling. Comparison of the two application methods has yielded mixed results and warrants further research. Therefore, the objectives of this research were to contrast the surface broadcast and subsurface injection of dairy slurry on nitrogen and carbon cycling, crop yield, and biologic responses to proxy soil health. In a forced air-flow laboratory incubation, manure injection reduced ammonia volatilization by 87% and 98% in a sandy loam and clay loam soil, respectively. The increased ammoniacal nitrogen recovery resulted in increases of soil nitrate of 13% for the sandy loam and 26% for the clay loam after 40 days of incubation. Microbial measurements were inconclusive in the laboratory. In 7 site-years of field study, soil nitrate was greater in 7 of 25 measurements under manure injection and 30% higher under injection on average during the corn pre side-dress nitrate test (PSNT) time. Soil nitrate sampling methods were assessed for fields injected with manure; a standard random sampling method had a coefficient of variation (C.V.) of 28% and was as equally repeatable as utilizing an equi-spaced distribution of cores taken across an injection band, C.V. of 30%. Both biological responses, carbon mineralization
(C-min) and substrate induced respiration (SIR), were not different between application methods; both were highly variable and C-min was especially intensive logistically. Corn yield showed no consistent response to application method, but probably was not nitrogen limited. In 2 years of field study conducted on a university research farm injection resulted in greater 0-15cm soil nitrate levels than surface broadcast 1 week after application and persisted for 9 additional weeks. In injected plots, nitrate was concentrated in the injection band; nitrate movement was significant only 10cm lateral to the injection band but overall distribution fit well to a second degree polynomial, especially 2 and 4 weeks after application, R2>0.80. Evidence of leaching was observed in one year after receiving considerable rainfall in weeks 1 and 2 after application. When corn grain yield was averaged year over year, injection was 26% greater than the no- manure control, and 15% greater than surface application. Both biological metrics, C-min and microbial biomass, were stratified by depth; C-min was concentrated within the manure band leading to greater mineralization under injected applications. Microbial biomass was significantly higher under injection at the 15-30cm depth. Overall biological response to manure application method was inconclusive, however manure injection is superior to surface application in terms of nitrogen recovery.Doctor of Philosophy
Animal manures supply nutrients essential to crop growth (notably nitrogen and phosphorous); liquid manures (pigs and dairy cattle) are commonly applied by spraying them on soils before tillage. Where no-tillage is used as a conservation measure subsurface injection can be used as an alternative to leaving manure on the soil surface. The purpose of this research was to assess nutrient cycling, crop yield, and soil health impacts of surface applied and injected dairy manure applications. Manure injection greatly reduces a nitrogen loss pathway, and as a result supplies more plant available nitrogen to the crop. Methods of soil sampling fields using injection were compared and a recommended sampling method was defined. Transport of a form of nitrogen vulnerable to movement in the ground was found to only travel 10cm away from where manure was injected. Transport of this form of nitrogen below the injection area was observed after abundant rainfall. Crop yields were sometimes higher under injection however, yields are also determined by factors other than nitrogen. Soil health was not repeatably improved under one application method, but microbial activity was greater at shallower soil depths.
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Al-Hosiny, Najm M. "Nonlinear dynamics of a distributed feedback laser subject to single and dual optical injection." Thesis, University of Essex, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.434393.
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Modak, Ghabiba. "Characterisation of dynamics associated with skeletal muscle contraction initiated by Acetylcholine injection Ghabiba Modak." Master's thesis, University of Cape Town, 2011. http://hdl.handle.net/11427/11994.
Повний текст джерелаАнотація:
Includes abstract.Includes bibliographical references.
Lower motor neuron damage often results in flaccid paralysis in which the affected muscles are unable to be stimulated artificially via the supplying nerve. Such damage is common in patients who suffer from spinal cord injury and Multiple Sclerosis. Current practice for artificial recovery of muscle function involves stimulating the muscles directly by means of Functional Electrical Stimulation (FES), which requires 100-1000 times more current than that required for nerve stimulation, thus presenting the risk of pain receptor activation. A potential alternative exists in chemical stimulation by means of administration of the neurotransmitter, Acetylcholine (ACh). This study investigates the potential of this possibility by examining the response of two muscle types to extracellular administration of ACh.
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Vignat, Guillaume. "Injection and combustion dynamics in swirled spray flames and azimuthal coupling in annular combustors." Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASC024.
Повний текст джерелаАнотація:
Le déploiement de technologies à faibles émissions dans les moteurs d’avion ne nécessite pas seulement que les nouvelles conceptions émettent des quantités réduites de polluants, mais également que leur comportement dynamique (allumage, extinction et instabilités de combustion) soit compatible avec les normes de sécurité élevées en vigueur dans l’aéronautique. Ce travail de recherche se concentre sur ces derniers aspects. Une chambre annulaire transparente équipée de 16 injecteurs swirlés représentant à échelle réduite le foyer d’un moteur d’hélicoptère est utilisée conjointement avec un système à un seul secteur pour étudier les problèmes dynamiques. Théorie, expérimentation et simulation aux grandes échelles sont combinées pour examiner une gamme de questions ayant trait à la dynamique de l’injecteur, la structure de l’écoulement, la détermination du niveau de rotation, les caractéristiques du spray, le couplage entre l’injection et le champ acoustique. Une base de données d’injecteurs est introduite pour étudier l’impact des paramètres d’injection sur la dynamique de la combustion. Ces injecteurs sont examinés dans des conditions stables et instables en combinant des diagnostics laser et des simulations permettant la caractérisation de comportements spécifiques à la dynamique du spray et du système d’injection. Un résultat important est que la présence d’un film liquide formé sur la paroi de l’injecteur induit une distribution multimodale des vitesses des gouttelettes. Une nouvelle méthode est introduite pour examiner le comportement spatio-temporel de l’écoulement et de la flamme lorsque l’injecteur est soumis à des modulations axiales. Une étude du processus par lequel les perturbations convectives se couplent au champ acoustique permet d’examiner les délais qui contrôlent l’instabilité de combustion et d’identifier les rôles respectifs de la convection et de l’évaporation des gouttes. La tomographie à grande vitesse reposant sur des particules de SnO2 fournit des résultats majeurs sur la structure du noyau tourbillonnaire en précession et montrent son comportement sous forçage acoustique. L’impact de la perte de charge de l’injecteur sur les instabilités de combustion est examiné à l’aide de plusieurs systèmes d’injection avec des niveaux de rotation semblables. Il est démontré que ce paramètre joue un rôle majeur dans le couplage entre la flamme et le plénum. Les résultats précédents sont utilisés pour guider les expériences sur la chambre de combustion annulaire. L’accent est mis sur les oscillations de combustion de grande amplitude couplées par un mode azimutal stationnaire induisant une extinction de flamme au voisinage de la ligne nodale de pression. La déformation du champ acoustique est suivie à l’aide d’une développement en série d’harmoniques azimutaux permettant la détermination des conditions critiques conduisant à ce phénomène. De nouveaux résultats sont également présentés sur la dynamique transitoire d’un injecteur lors de l’allumage et sur l’extinction pauvre avec une preuve de concept de la possibilité d’étendre la limite d’extinction par des décharges plasma nanosecondeThe deployment of low-emission technologies in aero-engines does not only require that new designs produce reduced amounts of pollutants, but also that their dynamical behavior (ignition, blow-off, and combustion instabilities) be compatible with the high safety standards prevailing in aeronautics. This research is focused on the latter aspect of combustor design. A transparent annular combustor equipped with 16 swirled spray injectors is used to represent at the laboratory scale the combustion chamber of a jet engine. This system is used in conjunction with a single sector rig to investigate dynamical issues.Theory, experimentation and large eddy simulation are combined to examine a range of items pertaining to the injector dynamics, flow structure, swirl number determination, spray characteristics, and coupling between injector flow and acoustic field. A database of injectors is introduced to investigate the impact of injection parameters on combustion dynamics. These injectors are examined under steady and unsteady conditions by combining laser diagnostics and high-fidelity simulations which allows the characterization of spray-specific behaviors of relevance to the dynamics of injection systems. One important result is that the presence of a liquid film formed on the wall of the injection unit gives rise to a multi-modal distribution of droplet velocities. A novel method is introduced to examine the space-time behavior of the flow and flame of a swirling injector submitted to axial modulations. A detailed investigation of the process by which convective perturbations couple with the acoustic field allows to examine the time lags that control combustion instability and sort out the respective roles of convection and droplet spray evaporation. High speed tomography relying on SnO2 particles provides major results on the Precessing Vortex Core structure and show its behavior under acoustic forcing. The impact of injector head loss on combustion instabilities is examined using several injection systems with similar levels of swirl. The head loss is shown to play a major role in the coupling between the flame and the upstream plenum. The previous results obtained in a single sector rig are used to guide experiments on the annular combustor. The focus is placed on high amplitude combustion oscillations coupled by a standing azimuthal mode inducing flame blow-off near the pressure nodal line. The deformation of the acoustic distribution is tracked using a novel expansion on azimuthal harmonics allowing the determination of the critical conditions leading to this phenomenon. New results are also presented about the transient dynamics of an injector during ignition and about lean blow out with a proof of concept extension of the LBO limit by nanosecond plasma discharges
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Konstantinou, Konstantinos I. "Seismological studies of magma injection processes : volcano monitoring and imaging of magma chambers." Thesis, Durham University, 2001. http://etheses.dur.ac.uk/3847/.
Повний текст джерелаАнотація:
The processes associated with magma injection at shallow depths within the crust have been the topic of many geophysical studies, some investigating the seismicity that accompanies volcanic activity and others attempting to map the subsurface extent and geometry of the resulting magma bodies. The aim of this study is to obtain a better understanding of these processes by investigating the nature of seismic signals that accompany volcanic eruptions and by seismically imaging a magma body beneath a mid-ocean ridge, both located on, or adjacent to Iceland. The seismic phenomena associated with the 1996 Vatnajӧkull subglacial eruption in central Iceland, have been studied using data recorded by both temporary (HOTSPOT) and permanent (SIL) seismic networks. These networks comprise 60 broadband and short-period three-component seismographs and cover most parts of the country. Two very active volcanic systems, Bárdarbunga and Grimsvӧtn, are situated underneath the Vatnajokull ice cap. The volcanoseismic signals recorded there were categorised according to their waveform shape and frequency content, into three groups: (a) low-frequency events (1-2 Hz); (b) mixed-frequency events (1-4 Hz); and (c) volcanic tremor. The eruption was preceded by intense seismic activity which began with a = 5.6 earthquake located at the Bárdarbunga volcanic system. The epicentres of the earthquake swarm that followed the M(_w), = 5.6 event initially delineated the Bárdarbunga caldera rim and then migrated towards Grimsvӧtn, to a place where a fissure was later observed. Pre-eruptive tremor started at least two days before the eruption as a harmonic signal around five narrow frequency bands (0.5-0.7, 1.6, 2.2, 2.8 and 3.2 Hz). Co-eruptive tremor started as a broadband, continuous signal which evolved into low-amplitude background tremor interrupted by high-amplitude, cigar-shaped bursts. Further analysis revealed that continuous tremor and the cigar-shaped bursts had all the characteristics of low- dimensional chaotic signals. Geophysical and geochemical evidence suggest that a lateral migration of magma from Bárdarbunga facilitated the rupture of the roof of a magma chamber, situated at the fissure area, which subsequently erupted as tephra on the glacier. The second phase of the RAMESSES (Reykjanes Ridge Axial Melt Experiment: Structural Synthesis from Electromagnetic and Seismics) experiment involved the acquisition of multichannel seismic reflection data from 39 along- and across-axis lines shot over the magmatically active 57º 45'N axial volcanic ridge. The data from one along-axis line were processed using a variety of techniques that mainly aimed at reducing the large amount of coherent noise present, a result of scattered energy at the rough seabed. The final processed section revealed a number of reflection events that could be interpreted as intra-crustal reflections, originating from the interface between pillow lavas and sheeted dykes, and from the top part of a thin melt lens.
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Rife, M. E. "Large eddy simulations of high Reynolds number jets with microjet injection." Thesis, Loughborough University, 2014. https://dspace.lboro.ac.uk/2134/14686.
Повний текст джерелаАнотація:
Continued growth of the aviation industry and increasingly strict noise requirements set by international bodies and airport authorities alike means that novel methods of reducing aircraft noise must be found. Engine noise represents a majority contribution to total aircraft noise during take-off and turbulent mixing of the exhaust gases is the dominant noise source of the engine at take-off. While bypass ratio has been the historical, and rather convenient means, of reducing jet noise, an upper limit to bypass ratio is now being approached and additional means of reducing jet noise must be found. One method that has shown potential for reducing aeroacoustic jet noise is the application of small, high pressure jets to the circumference of the jet nozzle. These jets, termed microjets, have the advantage over static devices that the microjets can be activated only when the noise benefit is required and deactivated when emitted noise is not an issue, such as in cruise, thereby reducing the thrust penalty associated with the devices over the majority of the flight. Large eddy simulations have been performed to investigate the impact that the addition of microjets has on the aerodynamic flowfield and radiated far-field noise of a high Reynolds number, Mach 0.9, propulsive, laboratory scale jet. Far-field noise was predicted through a new implementation of the permeable Ffowcs Williams Hawkings surface method in the solver. In addition to single-point flowfield statistics and far-field noise, spatio-temporal second- and fourth-order correlations are investigated. Two pairs of simulations were conducted, a coarse mesh containing 100 million elements and a fine mesh with 200 million elements. The coarse mesh included an azimuthal clustering of the cells in the near-microjet region. The non-uniformity of the azimuthal cell size was shown to adversely affect the development of the initial shear layer, yielding a delay in transition to a fully turbulent state and larger coherent structures in regions with larger cells. Radial velocity and turbulent kinetic energy profiles show good agreement with experimental results. A previously unidentified periodic interaction between the main jet and microjets was found. The dynamic interaction gives rise to velocity and pressure fluctuations in the near microjet region that match a tonal frequency found in the microjet far-field spectra that is absent from the clean jet case. Second- and fourth-order correlation distributions show large periodic regions of high correlation amplitude in the near microjet region. The evidence demonstrates that the main-microjet interaction is a clear high-frequency noise source. Despite the high-frequency noise associated with the main-microjet interaction, the addition of microjets yields a 1-2 dB reduction in overall sound pressure level. Additionally, over a significant portion of the length of the potential core the microjets reduce the amplitude of the majority of the six main correlation amplitudes that can be used in far-field noise prediction. Finally, the generation of the counter-rotating vortex pair downstream of the microjets was investigated. It is commonly presumed that this vortex pair is similar in origin to the counter-rotating vortex pair present in a jet in a crossflow. Vortex identification methods, velocity vectors and streamlines in the near microjet region demonstrate that the horseshoe-like vortex is the source of the counter rotating vortex pair that is present downstream of the microjets. The horseshoe-like vortex in the microjet case has the same sense as the vortices in the microjet shear layer and appears to be generated by the development of a recirculation region of microjet fluid during the main-microjet interaction.
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Chishty, Wajid Ali. "Effects of Thermoacoustic Oscillations on Spray Combustion Dynamics with Implications for Lean Direct Injection Systems." Diss., Virginia Tech, 2005. http://hdl.handle.net/10919/28089.
Повний текст джерелаАнотація:
Thermoacoustic instabilities in modern high-performance, low-emission gas turbine engines are often observable as large amplitude pressure oscillations and can result in serious performance and structural degradations. These acoustic oscillations can cause oscillations in combustor through-flows and given the right phase conditions, can also drive unsteady heat release. This coupling has the potential to enhance the amplitude of pressure oscillations. To curb the potential harms caused by the existence of thermoacoustic instabilities, recent efforts have focused on the active suppression and even complete control of these instabilities. Intuitively, development of effective active combustion control methodologies is strongly dependent on the knowledge of the onset and sustenance of thermoacoustic instabilities. Specially, non-premixed spray combustion environment pose additional challenges due to the inherent unstable dynamics of sprays. The understanding of the manner in which the combustor acoustics affect the spray characteristics, which in turn result in heat release oscillation, is therefore, of paramount importance. The experimental investigations and the modeling studies conducted towards achieving this knowledge have been presented in this dissertation.
Experimental efforts comprise both reacting and non-reacting flow studies. Reacting flow experiments were conducted on a overall lean direct injection, swirl-stabilized combustor rig. The investigations spanned combustor characterization and stability mapping over the operating regime. All experiments were performed under atmospheric pressure condition, which is considered as an obvious first step towards providing valuable insights into more intense processes in actual gas turbine combustors. The onset of thermoacoustic instability and the transition of the combustor to two unstable regimes were investigated via phase-locked chemiluminescence imaging and measurement and phase-locked acoustic characterization. It was found that the onset of the thermoacoustic instability is a function of the energy gain of the system, while the sustenance of instability is due to the in-phase relationship between combustor acoustics and unsteady heat release driven by acoustic oscillations. The presence of non-linearities in the system between combustor acoustic and heat release and also between combustor acoustics and air through-flow were found to exist. The impact of high amplitude limit-cycle pressure on droplet breakdown under very low mean airflow and the localized effects of forced primary fuel modulations on heat release were also investigated.
The non-reacting flow experiments were conducted to study the spray behavior under the presence of an acoustic field. An isothermal acoustic rig was specially fabricated, where the pressure oscillations were generated using an acoustic driver. Phase Doppler Anemometry was used to measure the droplet velocities and sizes under varying acoustic forcing conditions and spray feed pressures. Measurements made at different locations in the spray were related to these variations in mean and unsteady inputs. The droplet velocities were found to show a second order response to acoustic forcing with the cut-off frequency equal to the relaxation time corresponding to mean droplet size. It was also found that under acoustic forcing the droplets migrate radially away from the spray centerline and show oscillatory excursions in their movement.
Non-reacting flow experiments were also performed using Time-Resolved Digital Particle Image Velocimetry to characterize modulated sprays. Frequency response of droplet diameters were analyzed in the pulsed spray. These pilot experiments were conducted to assess the capability of the system to measure dynamic data.
Modeling efforts were undertaken to gain physical insights of spray dynamics under the influence of acoustic forcing and to explain the experimental findings. The radial migration of droplets and their oscillatory movement were validated. The flame characteristics in the two unstable regimes and the transition between them were explained. It was found that under certain acoustic and mean air-flow condition, bands of high droplet densities were formed which resulted in diffusion type group burning of droplets. It was also shown that very high acoustic amplitudes cause secondary breakup of droplets.Ph. D.
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Bellan, Luca. "Beam Dynamics Characterization of the IFMIF/EVEDA RFQ Input Beam." Doctoral thesis, Università degli studi di Padova, 2018. http://hdl.handle.net/11577/3425290.
Повний текст джерелаАнотація:
The high intensity accelerators are one of the world-wide leading edge research in the beam dynamics studies. The upgrades of the existing accelerator LINAC4, FERMILAB, FAIR and the new applications on the neutron technologies such as ESS, IFMIF, MUNES, both for science research, medical treatment and material testing require an increase knowledge in the high intensity beams treatment. One of the most difficult part to be treated and which represent the first obstacle in increasing the beam intensity in the accelerators, is the injector part: the large number of charge particles at low energy forms a strongly interacting system, subjected to the Coulombian interaction. The situation further complicates due to the presence of different species which produces a plasma-like behavior of the beam. On the behalf of the INFN-LNL team, I participated to the commissioning of the high intensity injector (source and low energy transfer line) of the IFMIF/EVEDA project. Via experiments and simulation model developments I contributed to the study of the beam behavior in this specific framework. In particular I upgrade the emittance measurement routine in order to manage correctly the artifacts; I develop and benchmark with measurements self-consistent simulation models of the LEBT and extraction transfer line, which includes the secondary
electron from residual gas and from metal due to collisions; I design a modification of medium and high energy line in order to test the CW steady state of the longest radio frequency quadrupole in the world, an in-kind contribution of INFN. All the development routines and experience will give important contributions for the next high intensity facilities. The first
chapter presents the motivation of the IFMIF project and the main characteristics required by the accelerator. The main challenges of such accelerator are also listed. The second chapter introduces the main concepts of the beam dynamics of space-charge which will be used in
the thesis. The third chapter presents the IFMIF/EVEDA project, with a description of the main elements; particular focus is made onto the source, the low energy beam transfer line and on the radio frequency quadrupole. Scaling law derivation for the extracted beam with contaminants is shown. The commissioning phases are introduced, each with its specific
challenges. The fourth chapter presents the modification of the emittance analysis routine which can manage the ghost infested signal of the IFMIF/EVEDA emittancemeter. The fifth and the sixth chapters contains the simulation models developed to estimate the space-charge
beam behavior under neutralization regime: the model with constant neutralization and the one with the full secondary plasma evolution are presented and benchmarked with the measurements. In the fifth chapter the measurements refers to 60−55 mA proton beam at 50 keV, while for the sixth chapter the beam considered is composed of 140−135 mA deuteron beam at 100 keV. In these chapters, the variation of the radio frequency quadrupole beam input characteristics with respect to the electromagnetic plasma confinement of the low energy transfer line is studied. The original contribution in these simulations is given by the emitted secondary electron from metal, which as some effects on the space charge compensation process, on the emittance value. Deep study of the multispecies distributions and behavior was performed. The four chapter defines, for the experimental proton point considered, the
solenoid variations where searching the maximum radio frequency quadrupole transmission. The output beam behavior of this one is studied in commissioning perspective. In thesixth chapter, after testing the radio frequency quadrupole transmission with the secondary plasma model (also said dynamic neutralization model) with a realistic beam distribution, the
simulations of the extraction system are presented. The benchmark with the measurements are also performed. The seventh chapter presents the design of the modification of the medium and high energy transfer sections of the accelerator in order to allow the test of the CW of the radio frequency quadrupole, bypassing the superconductive cavities. Extensive
simulations of the system robustness to the errors are explored. The last chapter reports the conclusions.Gli acceleratori ad alta intensità sono oggetto di ricerche all'avanguardia a livello mondiale nel campo degli studi di dinamica di fascio. Gli upgrade degli acceleratori esistenti LINAC4, FERMILAB, FAIR e le nuove applicazioni che utilizzano fasci di neutroni come ESS, IFMIF, MUNES, sia per la ricerca scientifica sia per cure mediche che per le prove sui materiali, richiedono un aumento delle conoscenze nella trattazione dei fasci ad alta intensità. Una delle parti più difficili da trattare è la parte dell'iniettore: le particelle dei fasci ad alta intensità a bassa energia sono sottoposte ad una forte interazione coulombiana. La situazione si complica ulteriormente a causa della possible presenza di diverse specie, le quali producono un comportamento plasma-like del fascio. Per conto del team INFN-LNL, ho partecipato al collaudo dell'iniettore (sorgente e linea di trasferimento a bassa energia) del progetto IFMIF / EVEDA. Tramite esperimenti e sviluppi del modello di simulazione, ho contribuito allo studio del comportamento del fascio in questo quadro specifico. In particolare, ho migliorato la routine di misura di emittenza al fine di gestire correttamente gli artefatti generati dai fasci ad alta intensità; ho sviluppato e confrontato con misure di fascio i modelli auto-consistenti di simulazione della linea di trasferimento e dell'estrazione, includendo gli elettroni secondari generati (a causa di interazioni con il fascio) sia dal gas residuo che dal metallo; ho studiato una modifica della line a media ed alta energia, in modo tale da testare il regime CW del quadrupolo a radio-frequenza (il più lungo al mondo), contributo al progetto dell'INFN. Tutti gli studi che ho effettuato e l'esperienza acquisita rappresentano un contributo importante per le prossime facility ad alta intensità. Il primo capitolo presenta la motivazione del progetto IFMIF e le principali caratteristiche richieste dall'acceleratore. Sono elencate anche le principali sfide di tale acceleratore. Il secondo capitolo introduce i concetti principali della dinamica di fascio in regime di space-charge. Il terzo capitolo presenta il progetto IFMIF/EVEDA, con una descrizione degli elementi principali dell'acceleratore; particolare attenzione è rivolta alla sorgente, la linea di trasferimento del fascio di bassa energia e del quadrupolo a radiofrequenza. La derivazione di una fromula teorica per scalare l'ottica del fascio estratto, in presenza di contaminati, viene presentata e succesivamente validata. Vengono introdotte le fasi del collaudo, ognuna con le sue specifiche sfide. Il quarto capitolo presenta la modifica ed implementazione della routine di analisi delle emittanze, la quale può gestire il segnale ottenuto con presenza di artefatti. Il quinto ed il sesto capitolo contengono i modelli di simulazione sviluppati per stimare la carica spaziale ed il comportamento del fascio in regime di neutralizzazione di space-charge: il modello con neutralizzazione costante e quello con l'evoluzione del plasma secondario vengono presentati e confrontati con le misure. Nel quinto capitolo, le misure di riferimento riguardano un fascio protonico di 60-55 mA a 50 keV, mentre nel sesto capitolo il fascio considerato è composto da deutoni di 140-135 mA a 100 keV. In questi capitoli è studiata la variazione del comportamento del fascio all'input dell'RFQ, rispetto al confinamento elettromagnetico del plasma nella linea di trasferimento a bassa energia di trasferimento. Il contributo originale in queste simulazioni è dato dall'inclusione dell'effetto degli elettroni secondari emessi dal metallo, il quale agisce direttamente sulla compensazione della carica spaziale. Viene inoltre presentato uno studio approfondito delle distribuzioni e dei comportamenti delle diverse specie presenti nella line durante il processo di neutralizzazione. Il capitolo quattro definisce, per il fascio protonico sperimentale considerato, le variazioni dei solenoidi per ottenere la massima trasmissione attraverso l'RFQ. Il comportamento del fascio in uscita dall'RFQ è stato anche esso studiato. Nel sesto capitolo, dopo aver testato la trasmissione dell'RFQ con la distribuzione di fascio ottenuta dal modello di neutralizzazione dinamica, vengono presentate le simulazioni del sistema di estrazione. Il settimo capitolo presenta il design della modifica delle line di trasferimento a media e alta energia dell'acceleratore, in modo tale da consentire il test del regime CW RFQ. I risultati di estese simulazioni Montecarlo, ottenute per stimare la robustezza del design rispetto agli errori meccanici e magnetici, sono inoltre incluse. L'ultimo capitolo riporta le conclusioni.
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D'Agostino, Grazia. "Orbit dynamics studies of injection, acceleration and extraction of high-intensity beams for the upgrade of the INFN-LNS Superconducting Cyclotron." Doctoral thesis, Università di Catania, 2019. http://hdl.handle.net/10761/4122.
Повний текст джерелаАнотація:
The nuclear research carried out at the LNS laboratory in Catania is mainly allowed by the ion beams delivered by two ion accelerators, a 15 MV Tandem and a k800 Superconducting Cyclotron (the so-called CS). These accelerators deliver to the INFN-LNS scientific community a large variety of stable ion beams with energies ranging from a few MeV/amu to 80 MeV/amu.
NUMEN, a nuclear physics project born recently at INFN-LNS, proposes the use of the heavy ion induced double charge exchange reactions as a tool to access quantitative information relevant for nuclear matrix elements for neutrinoless double beta decay. The pilot experiment carried out by the NUMEN team at LNS in Catania has already demonstrated that beam power of the order of 1-10 kW of Carbon, Oxigen and Neon with energies in the range 15-70 MeV/amu are mandatory for the NUMEN reaction study. An additional requirement is that the beam energy resolution should not overcome 1/1000 FWHM.
Currently, the maximum CS beam power does not exceed 100 W, so a substantial upgrade of the CS is needed to fulfil the NUMEN requirements. In the frame of the CS upgrade, this thesis is devoted to the simulations of beam dynamics in the LNS cyclotron, with the aim to overcome the current CS limitations and to propose innovative solutions for achieving the beam characteristics in terms of beam power and energy resolution required by the NUMEN project.
In this thesis, one of the main topic is the stripping extraction from the CS. The study has allowed to individuate: i) the stripper foil position for each ion to be extracted by stripping, ii) the transverse dimension and direction of the new extraction channel in the CS to be used for all the ions to be extracted by stripping and iii) the features of the magnetic channels to be installed inside the new extraction channel.
The second subject of this thesis is the beam injection and acceleration up to the extraction in the LNS cyclotron. This study has been possible thanks to the development of the beam tracking model of the INFN-LNS Superconducting Cyclotron, performed in collaboration with the Ion Beam Applications company. This work has shown that the total transmission efficiency from the CS bore injection up to the extraction system, simulating also a process of energy selection outside the CS according to the NUMEN requirement, is only around the 2.7%, a low value compared to the expected value of 15%. The energy selection process is the main cause of the low total efficiency.
We demonstrated that the major contribution to the beam energy spread at the extraction in the LNS cyclotron is due to the large emittance circulating in the LNS cyclotron. The energy gain per turn contributes only partially to the energy spread at the extraction but, in any case, it sets an inferior limit on the minimum energy spread obtainable in the CS cyclotron. This value stays around 0.2%, about the twice of the NUMEN requirement.
This thesis allows also to establish a roadmap of the goals and milestones to be achieved in next months/years. According to the simulation results, the goal of reduction of the beam energy spread at the extraction can be achieved only paying attention on the ion beam production and transport to the CS, since these processes determine the emittance in the horizontal and vertical phase spaces of the beam entering the CS central region. Also a good quality of the accelerated beam will be necessary since an initial beam offset in the central region implies a further increase of the beam energy spread at the extraction. This work has also shown that an increase of the injection efficiency is possible by applying higher dee voltages than the nominal one and modifying slightly the existing central region design. These changes have allowed to increase the injection efficiency up to a factor of about 1.7.
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Zhang, Fengshou. "Pattern formation in fluid injection into dense granular media." Diss., Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/43716.
Повний текст джерелаАнотація:
Integrated theoretical and experimental analysis is carried out in this work to investigate the fundamental failure mechanisms and flow patterns involved in the process of fluid injection into dense granular media. The experimental work is conducted with aqueous glycerin solutions, utilizing a novel setup based on a Hele-Shaw cell filled with dense dry sand. The two dimensional nature of the setup allows direct visualization and imaging analysis of the real-time fluid and grain kinematics. The experimental results reveal that the fluid flow patterns show a transition from simple radial flow to a ramified morphology while the granular media behaviors change from that of rigid porous media to localized failure that lead to development of fluid channels. Based on the failure/flow patterns, four distinct failure/flow regimes can be identified, namely, (i) a simple radial flow regime, (ii) an infiltration-dominated regime, (iii) a grain displacement-dominated regime, and (iv) a viscous fingering-dominated regime. These distinct failure/flow regimes emerge as a result of competition among various energy dissipation mechanisms, namely, viscous dissipation through infiltration, dissipation due to grain displacements, and viscous dissipation through flow in thin channels and can be classified based on the characteristic times associated with fluid injection, hydromechanical coupling and viscoelastoplasticity.
The injection process is also analyzed numerically using the discrete element method (DEM) coupled with two fluid flow scheme, a fixed coarse grid scheme based on computational fluid dynamics (CFD) and a pore network modeling scheme. The numerical results from the two complementary methods reproduce phenomena consistent with the experimental observations and justify the concept of associating the displacement regimes with the partition among energy dissipation mechanisms. The research in this work, though fundamental in nature, will have direct impacts on many engineering problems in civil, environmental and petroleum engineering such as ground improvement, environmental remediation and reservoir stimulation.
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Comer, Adam Landon. "Optimisation of liquid fuel injection in gas turbine engines." Thesis, University of Cambridge, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.607844.
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Otto, Christian [Verfasser], and Eckehard [Akademischer Betreuer] Schöll. "Dynamics of quantum dot lasers subject to optical feedback and external optical injection / Christian Otto. Betreuer: Eckehard Schöll." Berlin : Technische Universität Berlin, 2013. http://d-nb.info/1066546401/34.
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Dhilipkumar, Prethive Dhilip. "Effect of Endwall Fluid Injection on Passage Vortex formation in a First Stage Nozzle Guide Vane Passage." Thesis, Virginia Tech, 2016. http://hdl.handle.net/10919/72904.
Повний текст джерелаАнотація:
The growing need for increased performance from gas turbines has fueled the drive to raise turbine inlet temperatures. This results in high thermal stresses especially along the first stage nozzle guide vane cascade as the hot combustion products exiting modern day gas turbine combustors generally reach temperatures that could endanger the structural stability of these vanes and greatly reduce the vane life. The highest heat transfer coefficients in the vane passage occurs near the endwall, particularly in the leading edge-endwall junction where vortical flows cause the flow of hotter fluid in the mainstream to mix with relatively lower temperature boundary layer fluid. This work documents the computational investigation of air injection at the end wall through a cylindrical hole placed upstream of the nozzle guide vane leading edge-end wall junction. The effect of the secondary jet on the formation of the leading edge horseshoe vortex and the consequent formation of the passage vortex has been studied. For the computations, the Reynolds averaged Navier–Stokes (RANS) equations were solved with the commercial software ANSYS Fluent using the SST k-ω model. Total pressure loss coefficient and kinetic energy loss Coefficient contour plots at the exit of the cascade to estimate the effect of the endwall fluid injection on loss profiles at the vane cascade exit. Swirling strength contours were plotted at several axial chord locations in order to track the path of the passage vortex in and downstream of the vane cascade. Two different hole-positions (located at 1 hole diameter and 2 hole diameters from the leading edge) along a plane parallel to the incident flow were considered in order to study the effect of the hole position with respect to the vane leading edge-endwall junction. Three different streamwise hole inclination angles with respect to the mainstream flow direction were studied to identify the best angle for the injection of fluid through the endwall. This angle was combined with five different compound angles (0°, 30°, 45°, 60° and 90°) in order to study the effect of varying the compound angle on the leading edge vortex and the passage vortex. Each of the above studies were conducted at two different injected fluid-to-mainstream mass flow ratios (0.5% and 1%) in order to study the effect of varying injected flow rate on the formation of the leading edge vortex and the vane passage vortex. From the results it was observed that suitable selection of the secondary injection mass flow rate, injection angle and hole-position caused an absence of the leading edge horseshoe vortex and delayed migration of the passage vortex across the guide vane passage. Heat Transfer studies were also conducted to observe the absence/weakening of the leading edge vortex and the delayed pitch-wise movement of the passage vortex.Master of Science
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Mills, John Richard. "A mach 1.95 free-jet facility for experimental investigation of injectant flow patterns." Thesis, Virginia Tech, 1991. http://hdl.handle.net/10919/41997.
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Xia, You. "Experiments on EHD injection, interaction and electrocoalescence of water droplet pairs in oil." Thesis, Université Grenoble Alpes (ComUE), 2016. http://www.theses.fr/2016GREAI039/document.
Повний текст джерелаАнотація:
Lorsque des champs électriques sont appliqués à des mélanges eau-huile, les petites gouttelettes d'eau sont attirées entre elles et se regroupent en gouttes plus grosses. Ce processus d’électrocoalescence rend plus efficace la séparation huile-eau par sédimentation.Des données expérimentales sur l’électrocoalescence de très petites gouttelettes sont nécessaires pour améliorer la compréhension de la dynamique de l'interface eau-huile et pour valider les modèles numériques. La configuration simple étudiée dans ce travail de thèse concerne une petite paire de gouttelettes tombant dans une cuve d'huile modèle et soumise à un champ électrique aligné avec l’axe de symétrie des gouttes et la gravité.La première partie du travail a consisté à générer de façon contrôlée d’une paire de très petites gouttelettes (dans la gamme de diamètres 20-200 microns) alignée avec le champ électrique. La génération de goutte à la demande, par méthode éléctrohydrodynamique (EHD) a été améliorée pour un meilleur contrôle du diamètre et de la charge électrique des gouttelettes injectées à partir d'une aiguille métallique unique. Ceci a été obtenu en appliquant à un ménisque d'eau pendant à l’extrémité de l’aiguille des impulsions électriques de forme optimisée.La caractérisation électrique et hydrodynamique des paires de gouttelettes et leur coalescence sont alors principalement déduites de l'analyse des vitesses de chute, avec et sans application d’un champ électrique à courant continu. Des données complètes de positions des gouttelettes et de leur vitesse en fonction du temps sont déduites de prises de vues vidéo. Une attention particulière a été accordée aux visualisations de très petites gouttelettes tombant à petites vitesses, associant des angles multiples de prise de vue, de forts zooms et des vidéos à grande vitesse.La modélisation des différents termes d'interactions hydrodynamiques et électrostatiques entre les gouttelettes permet de déduire des vitesses enregistrées leur masse charge électrique respectives. Quand se produit une coalescence des deux gouttelettes, un enregistrement de la vitesse de la gouttelette résultante, avec et sans tension électrique appliquée, permet de contrôler la conservation de la masse et de la charge électrique, et la validation du procédé.Un premier ensemble de données est constitué d'environ 70 cas différents, avec différentes paire des gouttelettes (dans une plage de diamètre limitée de façon à ce que les vitesses de chute soient comprises entre 0,1 et 0,3 mm/s) et en faisant varier la tension appliquée à courant continu ou alternatif. L'analyse des résultats et des incertitudes expérimentales et un exemple de comparaison possible avec des simulations numériques utilisant le logiciel Comsol Multiphysics ™, permettent d'effectuer des recommandations pour les travaux futurs.Ce travail a été financé par le projet “Fundamental understanding of electrocoalescence in heavy crude oils”; coordonné par SINTEF Energy Research. Le projet a été soutenu par The Research Council of Norway, dans le cadre du contrat n °: 206976 / E30, et par les partenaires industriels suivants: Wärtsilä Oil & Gas Systems AS, Petrobras et Statoil ASAWhen electric fields are applied in oil-water mixtures small water droplets are attracted to others and merge in larger drops. This electrocoalescence process makes more efficient the oil-water separation by sedimentation.Experimental data on the electrocoalescence of very small droplets will be useful to improve the understanding of the dynamics of water-oil interface and to validate numerical models. The simple configuration studied consists in a small droplet pair falling in stagnant model oil, under electric field aligned with the symmetry axis of the droplet pair and the direction of gravity.First part of the work consisted in the well-controlled generation of very small droplet pair (range 20-200 microns) aligned with electric field. Droplet-on-Demand generation by EHD method was improved for a better control of the diameter and electric charge of droplets injected from a single metallic needle. This was obtained by applying to a pendant water meniscus optimized multistage high voltage electric pulses.Electrical and hydrodynamic characterization of the droplet pairs and their coalescence are then mainly deduced from the analysis of falling velocities, with and without applied DC electric field. A complete data set of droplet position and velocity is deduced from video. A special attention was paid to the visualizations of very small droplet and small falling velocities, involving multiple angle of view, strong zooming and high speed video.Modelling the different terms of hydrodynamic and electrostatic interactions between droplets allows deducing from the recorded velocities their respective mass and electric charge. When coalescence occurs, a record of the resulting single droplet velocity, with and without applied voltage, allows controlling the mass and charge conservations and validating the method.A first data set was constituted of about 70 different cases, with varying droplets pair (with a limited diameter range to remain with falling velocities between 0.1 and 0.3 mm/s) and varying applied DC or AC voltage. Analyses of the results and experimental uncertainties, and example of possible comparison with numerical simulations using Comsol Multiphysics™ software, allow performing some recommendations for future work.This work was funded by the project “Fundamental understanding of electrocoalescence in heavy crude oils”; co-ordinated by SINTEF Energy Research. The project was supported by The Research Council of Norway, under the contract no: 206976/E30, and by the following industrial partners: Wärtsilä Oil & Gas Systems AS, Petrobras and Statoil ASA
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Moreau, Julien. "Interaction entre un jet et un tourbillon compressé. Etude expérimentale de l'aérodynamique et de mélange." Phd thesis, Institut National Polytechnique de Toulouse - INPT, 2003. http://tel.archives-ouvertes.fr/tel-00007174.
Повний текст джерелаАнотація:
Les écoulements internes et le mélange prenant place pendant la phase de compression d'un cylindre moteur constituent des facteurs clés en vue de l'optimisation du moteur ainsi que des émission polluantes. Le cadre contractuel de ce travail est un projet collaboratif mettant en oeuvre les constructeurs automobiles (PSA, Renault) le CNRS ainsi que l'ADEME. Une installation expérimentale existante a été exploitée. Nous avons apporté des modification permettant de réaliser une injection directe au sein de la chambre. Nous avons pu rassembler une base de donnée importante et fiable. Des techniques d'imagerie laser ont été utilisées. Cette étude servira à répondre à mieux connaître la capacité de cette interactions à altérer les propriétés de transport et de non dissipativité de la structure tourbillonnaire à grande échelle attendue pour réaliser une stratification de la charge. Nous nous intéressons ici à l'interaction entre un spray et l'aérodynamique dans une situation modèle d'un moteur à pistons. Ainsi un jet rond monophasique modèle à été a été mis en place afin de respecter une analyse dans dimension permettant d'être représentatif de la situation réelle. Deux directions d'injections ont été testées afin d'étudier l'influence du jet sur l'écoulement Des mesures ont donc été effectuées pour mesurer les champs de vitesse (PIV) ainsi que les champs de fraction massique (PLIF) dans le plan de symétrie de la chambre. Afin de réaliser des mesures quantitatives de fluorescence, il était nécessaire de réaliser un étalonnage afin de connaître le coefficient d'absorption ainsi que le rendement de fluorescence du dopant utilisé (en l'occurrence de l'acétone). Ces mesures permettent une meilleure compréhension des phénomènes de transfert d'énergie entre le jet d'injection et la structure tourbillonnaire à grande échelle ainsi que de la modification du processus de rupture de cette dernière par l'injection. L'énergie moyenne est transférée vers les petites échelles durant un temps très cours. Puis il apparaît que la perturbation de la structure cohérente à grande échelle par l'injection provoque très tôt dans le cycle le processus de dissipation. Ainsi, le temps de dissipation est plus long entraînant un niveau d'énergie fluctuante en fin de compression après injection beaucoup plus faible que dans la situation de compression du vortex seul. Cette donnée est importante en ce qui concerne la combustion. Enfin, nous avons proposé l'utilisation de la Décomposition Orthogonale en modes Propres (POD) avec une approche globale sur la phase de compression ceci afin de disposer d'une base commune à l'ensemble des champs instantanés de cette phase. Une interpolation des champs est donc nécessaire pour unifier en taille tous les champs utilisés dans la décomposition. Le schéma linéaire apparaît comme celui permettant de minimiser les pertes d'énergie par l'interpolation. Cette analyse POD confirme les conclusions apportée auparavant en ce qui concerne les transferts d'énergie entre échelles et apparaît comme un outil efficace et prometteur dans l'étude des phénomènes transitoires comme celui ci.
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Heather, Andrew. "Numerical and physical analysis of liquid break-up and atomisation relating to pressure-swirl gasoline direct injection." Thesis, Loughborough University, 2007. https://dspace.lboro.ac.uk/2134/14401.
Повний текст джерелаАнотація:
This thesis presents detailed fuel spray investigations relating to an automotive Gasoline Direct Injection (GDI) pressure-swirl injector, employing a combination of numerical and physical analyses. The emphasis is placed on the near-nozzle in recognition that all later flow processes are dominated by this critical region. To enable the technology to maximise its potential, it is essential to further our understanding of the fundamental flow physics that govern the injection process, which remain largely unknown. The complexity of the spray process has led to many avenues of research. Simplified models are particularly suitable for parametric studies, allowing fast computation of some of the most important design parameters, such as nozzle discharge coefficient, cone angle and initial velocity. More complex methods such as Computational Fluid Dynamics (CFD) offer significantly more detail including the temporal and spatial evaluation of the flow field and fuel distribution, but at the cost of often lengthy computational time, and the need to tune models against physical evidence. Unfortunately none are able to describe all aspects of the injection event simultaneously. A considerable body of existing experimental data gathered under atmospheric conditions has been condensed and carefully presented to provide a comprehensive picture of injector operation. This comprises global spray performance data, spray imaging, and droplet velocity and size maps as a function of time after the Start Of Injection (SOl). These serve to provide a means to develop physical models and to correlate model predictions. Particular attention is drawn to the challenges faced by numerical methods to successfully predict the complex spray behaviour. A fundamental computational study employing the Volume Of Fluid (VOF) method describes droplet break-up under controlled conditions. By varying the Weber number of the flow the expected break-up mechanisms are recovered, and the numerics and case set-up tuned to offer a practical balance between the resource burden and solution accuracy. This paved the way to a detailed 3-D transient analysis of the near-nozzle region of a pressure-swirl injector. Computed results clearly identify the consecutive phases of the fuel spray development, from the initial unsteady jet through to the stable, swirling hollow cone formation. Comparison with experimental measurements revealed that the computational approach is able to capture the main qualitative features of the spray process.
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Yon, Jérôme. "Jet Diesel haute presssion en champ proche et lointain : Etude par imagerie." Phd thesis, Université de Rouen, 2003. http://tel.archives-ouvertes.fr/tel-00005366.
Повний текст джерелаАнотація:
L'étude expérimentale présentée dans ce mémoire a pour but d'améliorer la compréhension des processus d'atomisation du jet Diesel à haute pression d'injection (jusqu'à 100 MPa), en injection directe. En effet, la structure réelle du jet Diesel ainsi que les processus qui conduisent à son atomisation ne sont pas encore réellement connus. La variété des modèles rencontrés dans la littérature témoigne de cet état de fait. Cette méconnaissance résulte de la difficulté à diagnostiquer le jet Diesel, qui est particulièrement dense optiquement et dont les échelles caractéristiques de temps (»1 ms) et d'espace (»100 µm) sont réduites. Dans le cadre de ce travail de thèse, de nouveaux diagnostics basés sur le traitement d'images ont été développés pour analyser les phénomènes se produisant en champ proche (premiers millimètres du jet) et en champ lointain (spray formé au loin de l'injecteur). L'utilisation de différentes configurations tomographiques en imagerie défocalisée, couplées à un dispositif d'imagerie par transmission, permet d'observer, en champ proche, des poches cylindriques de cavitation réparties à proximité de l'interface. Un nouveau modèle de la structure interne du jet Diesel est ainsi proposé. Une analyse entropique reposant sur une série d'images sur lesquelles trois états physiques sont distingués (jet dense, phase liquide dispersée et phase gazeuse) permet la description de l'évolution d'une « surface d'atomisation primaire » le long du jet Diesel. Une analyse morphologique statistique de l'interface du jet permet une description du détachement ligamentaire du jet dense, en fonction du temps et de la pression d'injection. Un granulomètre a également été développé et appliqué à l'analyse du champ lointain. Ce granulomètre prend en compte les phénomènes de défaut de mise au point pour localiser spatialement les gouttes. Il autorise également une caractérisation morphologique des gouttes. L'application de ces diagnostics montre une diminution radiale des diamètres caractéristiques du spray présentant, par ailleurs, une faible dépendance à la pression d'injection et à l'instant de l'analyse, pendant la phase stationnaire de l'injection. En revanche, on observe une variation du comportement morphologique des gouttes dans le temps et avec la pression d'injection.
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Votaw, Zachary Steven. "Computational Study on Micro-Pilot Flame Ignition Strategy for a Direct Injection Stratified Charge Rotary Engine." Wright State University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=wright1347895074.
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Nicoud, Edouard. "Quantification de la stabilité de la combustion dans les moteurs essence à injection directe par simulation aux grandes échelles." Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLC062.
Повний текст джерелаАнотація:
L’industrie automobile se trouve aucentre des préoccupations environnementalesactuelles. Les moteurs essence à injection directeopérés en condition pauvres offrent un fortpotentiel en terme de réduction des émissions depolluants. En contrepartie, ils sont sujets à uneforte variabilité cyclique de combustion (CCV)qui ne peut être que partiellement étudiéeexpérimentalement. La simulation aux grandeséchelles (SGE) apparait comme une approchenumérique adaptée pour étudier de telsphénomènes, du fait de sa capacité naturelle àcapter les phénomènes instationnaires. Laprésente thèse se propose d’une part d’estimer lacapacité de la SGE à reproduire les CCVobservées expérimentalement, et d’autre part decontribuer à une meilleure compréhension deleur apparition. Dans ce contexte, un effortparticulier est mis sur la modélisation desphénomènes proche paroi. En particulier, unmodèle de paroi adapté à l’étude del’aérodynamique interne de configurationindustrielles est proposé. Il est validé sur desconfigurations de complexités variées. Enfin,l’étude porte sur le cas du moteur M256 qui estétudié en s’appuyant sur une solide base dedonnées expérimentales. Les causes de CCV sontexplorées, et notamment, l’impact de lavariabilité de l’écoulement généré pendant laphase d’admission sur la propagation du front deflamme est clarifiéThe automotive industry finds itselfat the center of current environmental concerns.Modern direct injection engines, operated underlean condition have the potential to reducepollutant emissions. As a drawback, they aresubject to large cyclic combustion variability(CCV), that can be explained only partially byexperimental measurements. Large-EddySimulation (LES) appears as an adapted tool tocomplement experiments, due to its naturalability to capture unsteady phenomena. Thepresent PhD thesis first aims at reproducing theCCV, and at contributing achieving a betterunderstanding of their occurrence.In this context, a special effort is put on thereproduction of near-wall phenomena, throughthe proposal of a new wall boundary conditionthat is validated on cases of differentcomplexity. Then the focus is put on the M256case, for which an extensive experimentaldatabase is available. The causes of CCV areexplored, and in particular, the impact of thevariability of the intake flow on the flame frontpropagation is clarified
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Mitori, Tiffany Leilani. "Flight and Stability of a Laser Inertial Fusion Energy Target in the Drift Region between Injection and the Reaction Chamber with Computational Fluid Dynamics." DigitalCommons@CalPoly, 2014. https://digitalcommons.calpoly.edu/theses/1154.
Повний текст джерелаАнотація:
A Laser Inertial Fusion Energy (LIFE) target’s flight through a low Reynolds number and high Mach number regime was analyzed with computational fluid dynamics software. This regime consisted of xenon gas at 1,050 K and approximately 6,670 Pa. Simulations with similar flow conditions were performed over a sphere and compared with experimental data and published correlations for validation purposes. Transient considerations of the developing flow around the target were explored. Simulations of the target at different velocities were used to determine correlations for the drag coefficient and Nusselt number as functions of the Reynolds number. Simulations with different target angles of attack were used to determine the aerodynamic coefficients of drag, lift, Magnus moment, and overturning moment as well as target stability. The drag force, lift force, and overturning moment changed minimally with spin. Above an angle of attack of 15°, the overturning moment would be destabilizing. At angles of attack less than 15°, the overturning moment would tend to decrease the target’s angle of attack, indicating the lack of a need for spin for stability at these small angles. This stabilizing moment would cause the target to move in a mildly damped oscillation about the axis parallel to the free-stream velocity vector through the target’s center of gravity.
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Chevalier, Christophe. "Dynamique et instabilités des interfaces grains/fluide dans les suspensions non-Browniennes." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2006. http://tel.archives-ouvertes.fr/tel-00144599.
Повний текст джерелаАнотація:
Depuis les premiers travaux d'Einstein en 1906, le comportement des suspensions granulaires macroscopiques a fait l'objet de nombreuses études notamment en rhéologie. Cependant, la question des mécanismes susceptibles d'intervenir aux interfaces de ces suspensions reste ouverte et peu abordée. C'est précisément l'objet de cette thèse.Nous proposons de sonder les propriétés d'une interface grains/fluide en injectant un fluide dans une suspension granulaire isodense dont nous contrôlons la fraction de grains. Cette suspension est confinée dans une cellule de Hele-Shaw et nous pouvons injecter soit de l'air soit du fluide interstitiel pur.
Pour les fractions de grains inférieures à 50%, l'injection d'air s'apparente à la digitation de Saffman-Taylor. Nous montrons que le mode de sélection des largeurs relatives et la stabilité des doigts sont modifiés par la présence des grains et que ces modifications ne peuvent se réduire à la simple considération d'un fluide effectif.
Pour les fractions plus importantes, des phénomènes de blocage liés au réseau des contacts entre grains apparaissent et nous nous trouvons dans le cas d'un milieu poreux réorganisable. L'écoulement de fluide peut alors se faire de deux façons : soit au travers de la structure granulaire restée fixe, soit en mobilisant en partie cette structure.
Dans le cas de l'injection d'air, des réarrangements localisés permettent d'obtenir des structures dont la taille dépasse celle des pores mais reste fine. Dans le cas de l'injection de fluide interstitiel pur, une mobilisation plus globale est observée qui mène à une décompaction homogène du milieu et à des structures de digitation plus larges.
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Moreno, Oscar Ray. "Investigation and development of oil-injection nozzles for high-cycle fatigue rotor spin test." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2005. http://library.nps.navy.mil/uhtbin/hyperion/05Mar%5FMoreno.pdf.
Повний текст джерелаАнотація:
Thesis (M.S. in Mechanical Engineering)--Naval Postgraduate School, March 2005.Thesis Advisor(s): Raymond Shreeve, Garth Hobson. Includes bibliographical references (p. 91-93). Also available online.
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Torré, Jean-Philippe. "Quenching runaway reactions : hydrodynamics and jet injection studies for agitated reactors with a deformed free-surface." Phd thesis, Toulouse, INPT, 2007. http://oatao.univ-toulouse.fr/7658/1/torre.pdf.
Повний текст джерелаАнотація:
To quench a thermal runaway reaction in a chemical rector, an efficient approach is the introduction of a small quantity of a liquid inhibiting agent, named a “killer”, into the mixing vessel. In this thesis, an experimental approach has been coupled tightly with numerical modelling using Computational Fluid Dynamics (CFD). The first part of this thesis is devoted to a study of the hydrodynamics of partially-baffled mixing vessels, including the free-surface deformation caused by the central vortex. The use of an inhomogeneous, multiphase approach allowed simulation of the free-surface deformation. The capability of this novel method was demonstrated by very good agreement between the numerical predictions and experimental data. In the second part, liquid jet injection at the free-surface was coupled with the vessel hydrodynamics. Numerical results, obtained using an Eulerian-Lagrangian approach, have again shown good agreement with experimental data. These results allowed the jet trajectory to be modelled and its penetration into the agitated vessel was quantified. New mixing criteria were introduced that are specific to this application. Finally, the numerical methods validated at the pilot scale were applied at the industrial scale and allowed the proposal of practical improvements to the safety of the synthesis reactors studied
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Nguyen, Cong Tu. "Spin dynamics in GaN- and InGaAs-based semiconductor structures." Thesis, Toulouse, INSA, 2014. http://www.theses.fr/2014ISAT0006/document.
Повний текст джерелаАнотація:
Ce travail de thèse est une contribution à l'étude de la dynamique de spin des porteurs dans des structures semiconductrices III-V en vue d’applications possibles dans le domaine émergent de la spintronique dans les semiconducteurs. Deux approches différentes on été envisagées afin de pouvoir obtenir une polarisation en spin des porteurs longue et robuste : i) le confinement spatial dans des nano-structures 0D (boîtes quantiques), ii) l’ingénierie des centres paramagnétiques dans des couches massives.Pour la première approche, nous avons étudié les propriétés de polarisation de spin d’excitons confinés dans des boîtes quantiques de GaN/AlN insérées dans des nano-fils. Nous avons d’abord mis en évidence un taux important de polarisation de la photoluminescence (15 %) à basse température sous excitation quasi-résonante et nous avons démontré que cette polarisation est temporellement constante pendant la durée de vie des excitons. Grâce à des mesures en température, nous avons aussi démontré que cette polarisation n’est aucunement affectée jusqu’à 300 K. Nous avons aussi développé un modèle détaillé basé sur la matrice densité pour décrire le dégré de polarisation de la photoluminescence et sa dépendance angulaire.Pour la deuxième approche, nous avons réalisé un dispositif prototype de filtrage de spin basé sur l’implantation de centres paramagnétiques dans des couches massives de InGaAs. Le principe repose sur la création de défauts interstitiels paramagnétiques comme précédemment démontré dans notre groupe pour les nitrures dilués tels que GaAsN. Le but de ce travail a été le développement d’un procédé de création de ces défauts qui puisse surmonter les inconvénients liés à l’insertion de l’azote dans les semiconducteurs de type GaAs : a) la dépendance de l’efficacité du filtrage de spin avec de l’énergie de photoluminescence, b) l’impossibilité de créer des zones actives avec des motifs spécifiques.Dans ce travail, nous démontrons que des régions actives de filtre à spin peuvent être créées par implantation ionique de défauts paramagnétiques avec une densité et des motifs spatiaux prédéfinis. Grâce à des études par photoluminescence, nous avons d’une part mis en évidence des taux de recombinaison dépendant en spin pouvant aller jusqu’à 240 % dans les zones implantées. D’autre part, nous avons déterminé la dose d’implantation la plus favorable grâce à une étude systématique sur différents échantillons implantés avec des densités ioniques étendues sur quatre ordres de grandeurs. Nous avons également observé que l’application d’un champ magnétique externe produit une augmentation significative du taux de recombinaison dépendant en spin due à la polarisation en spin des noyaux implantésThis thesis work is a contribution to the investigation by photoluminescence spectroscopy of the spin properties of III-V semiconductors with possible applications to the emerging semiconductor spintronics field. Two approaches have been explored in this work to achieve a long and robust spin polarization: i) Spatial confinement of the carriers in 0D nanostructured systems (quantum dots). ii) Defect engineering of paramagnetic centres in a bulk systems. Concerning the first approach, we have investigated the polarization properties of excitons in nanowire-embedded GaN/AlN quantum dots. We first evidence a low temperature sizeable linear polarization degree of the photoluminescence (~15 %) under quasi-resonant excitation with no temporal decay during the exciton lifetime. Moreover, we demonstrate that this stable exciton spin polarization is unaffected by the temperature up to 300 K. A detailed theoretical model based on the density matrix approach has also been developed to account for the observed polarization degree and its angular dependence.Regarding the second approach, we have demonstrated a proof-of-concept of conduction band spin-filtering device based on the implantation of paramagnetic centres in InGaAs epilayers. The principle relies on the creation of Ga interstitial defects as previously demonstrated in our group in dilute nitride GaAsN compounds. The driving force behind this work has been to overcome the limitations inherent to the introduction of N in the compounds: a) The dependence of the photoluminescence energy on the spin-filtering efficiency. b) The lack of spatial patterning of the active regions.In this work we show how the spin-filtering defects can be created by ion implantation creating a chosen density and spatial distribution of gallium paramagnetic centers in N-free epilayers. We demonstrate by photoluminescence spectroscopy that spin-dependent recombination (SDR) ratios as high as 240 % can be achieved in the implanted areas. The optimum implantation conditions for the most efficient SDR are also determined by the systematic analysis of different ion doses spanning four orders of magnitude. We finally show how the application of a weak external magnetic field leads to a sizable enhancement of the SDR ratio from the spin polarization of the implanted nuclei
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He, Lijun. "Analysis of the dynamics of the linear-and-rotary-motion energy-conversion systems with active DC excitation." Diss., Georgia Institute of Technology, 2015. http://hdl.handle.net/1853/54417.
Повний текст джерелаАнотація:
The objective of the dissertation is to develop simplified analytical models for typical linear-motion and rotary-motion energy-conversion systems under active DC excitation without tedious numerical-simulation effort, and provide practical implementation of the models in optimal-design and thermal-protection aspects.
The model of a vacuum automatic circuit recloser (a typical linear-motion system under DC excitation) is first developed in the form of a non-linear discontinuous eighth-order dynamic system. The model is then used to simulate the transient mechanical and electromagnetic performance during the opening and closing movements of the recloser. Such a model is not found in the literature.
Although the model is based on certain simplifying assumptions, the result is validated by high-speed-camera measurements. In addition, the impact of key design variables is explored, based on which an improved recloser design is proposed, and helps to optimize capital and production costs without degrading performance.
Further analytical investigation is carried out in modeling an inverter-fed induction motor (IM) (a typical rotary-motion system) with active DC injection. The IM is closed-loop controlled via two popular motor-control algorithms, namely, the direct-torque-control (DTC) algorithm and field-oriented-control (FOC) algorithm. Quantitative relationships between the changes of various machine variables during the active DC excitation are provided in the theoretical analysis. The developed DC-injection model is further simplified for practical implementation.
The developed IM model under DC injection results in practical ways to excite a proper amount of DC current directly or indirectly into IM stator windings via different closed-loop motor-control algorithms. In a DTC motor-drive system, the modeling work makes it possible to excite the DC current indirectly inside the motor by superimposing a stator-flux-linkage-bias command in the flux-control loop or a torque-ripple command in the torque-control loop. The proposed flux-linkage-injection and torque-injection methods are the first novel efforts to implement the DC-signal-injection method in a DTC motor-drive system. In addition, the analysis carried out in a standard FOC drive system brings about an improved DC-current-injection approach: the torque ripple in this method is significantly mitigated compared to all existing DC-injection methods in FOC systems.
The proposed DC-injection methods, either in a DTC or an FOC system, lead to a simple, low-cost, accurate, and non-invasive thermal-monitoring scheme for closed-loop-controlled IMs, where the stator temperature is indirectly estimated from stator resistance.
Furthermore, considering inverter non-idealities, there is a challenge for a typical inverter drive to accurately estimate the DC component of motor terminal voltages. The existing methods are extended to provide a complete study of the real-time signal-processing technique for both DTC and FOC algorithms, and are finally implemented in a custom-built programmable motor-drive system. The experimental results demonstrate that the proposed technique gives accurate and robust stator-temperature estimation, regardless of the operating conditions and cooling modes.
The analytical modeling method for the linear-motion and rotary-motion energy-conversion systems can be further extended to other power devices with similar mechanisms, and implemented in optimal design, control, and thermal-protection areas.
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Yeates, Christopher. "Multi-Scale Study of Foam Flow Dynamics in Porous Media." Thesis, Sorbonne université, 2019. http://www.theses.fr/2019SORUS023/document.
Повний текст джерелаАнотація:
Pour ce travail, nous utilisons un micromodèle à haute complexité et à structure fixe pour faire une série d’expériences en variant la vitesse d’injection, la qualité de la mousse, les distributions de taille de bulles d’injection, et la méthode d’injection. Nous mettons en œuvre un suivi individuel de bulles pour associer les propriétés d’écoulement aux propriétés de taille de bulles ainsi que les caractéristiques structurelles du milieu poreux. Nous proposons de nouveaux outils pour décrire l’écoulement d’un point de vue global et local de différentes manières. Nous établissons des comportements spécifiques à chaque taille de bulle, en montrant que les bulles des mousses piégées sont plus probables d’être de taille inférieure aux tailles de bulles moyennes, alors que les mousses en mouvement accèdent elles-mêmes à différents chemins d’écoulement selon les tailles de bulles. Les bulles plus volumineuses s’écoulent en majorité dans des chemins préférentiels à haute vitesse, généralement parallèles au gradient de pression, mais les petites bulles sont transportées en supplément à l’intérieur de chemins transversaux liant les chemins préférentiels. Ailleurs, pour nos données nous démontrons l’importance supérieure de la fraction de mousse piégée vis-à-vis de la densité de bulles quant à l’explication microscopique de la viscosité apparente, malgré une contribution des deux. Nous caractérisons structurellement les zones piégées à répétition, comme étant soit des zones à faible coordination de pore, de faible taille de seuil d’entrée, d’orientation de seuil désavantageuse, ou une combinaison de ceux-ci. Les zones à fort écoulement échappent à une caractérisation en termes de paramètres de structure locale et nécessitent une considération de l’information des différents chemins traversant la totalité du modèle. À ce but, afin de décrire les zones à fort écoulement, nous développons un modèle générant des chemins, utilisant une représentation en graphe du milieux poreux, basé sur une décomposition initiale en pores et seuils, qui intègre seulement les notions de taille de seuil et d’orientation de seuil relatif au gradient de pression pour caractériser les cheminsIn this work, we use of a high-complexity micromodel of fixed structure on which we perform a series of experiments with varying injection rates, foam qualities, inlet bubble size distributions and injection methods. We perform individual bubble tracking and associate flow properties with bubble size properties and structural characteristics of the medium. We propose new tools describing the local and global flow in different ways. We establish specific behaviors for different bubble sizes, demonstrating that trapped foams are more likely to have smaller than average bubble sizes, while flowing bubbles also tend to segregate in different flow paths according to bubble size. Larger bubbles tend to flow in high-velocity preferential paths that are generally more aligned with pressure gradient, but smaller bubbles tend to access in supplement transversal paths linking the different preferential paths. Furthermore, for our data we establish the pre-eminence of the trapped foam fraction over bubble density within the microscopic explanation of apparent viscosity, although both contribute to some degree. We structurally characterize consistently trapped zones as areas with either low pore coordination, low entrance throat size, unfavorable throat orientation or a combination thereof. High-flow zones however cannot be characterized in terms of local structural parameters and necessitate integration of complete path information from the entire model. In this regard, in order to capture the high-flow zones, we develop a path-proposing model that makes use of a graph representation of the model, from an initial decomposition into pores and throats, that uses only local throat size and throat orientation relative to pressure gradient to characterize paths
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Johnson, Perry L. "Toward increasing performance and efficiency in gas turbines for power generation and aero-propulsion unsteady simulation of angled discrete-injection coolant in a hot gas path crossflow." Honors in the Major Thesis, University of Central Florida, 2011. http://digital.library.ucf.edu/cdm/ref/collection/ETH/id/444.
Повний текст джерелаАнотація:
This thesis describes the numerical predictions of turbine film cooling interactions using Large Eddy Simulations. In most engineering industrial applications, the Reynolds-Averaged Navier-Stokes equations, usually paired with two-equation models such as k-Greek lowercase letter epsilon] or k-Greek lowercase letter omega], are utilized as an inexpensive method for modeling complex turbulent flows. By resolving the larger, more influential scale of turbulent eddies, the Large Eddy Simulation has been shown to yield a significant increase in accuracy over traditional two-equation RANS models for many engineering flows. In addition, Large Eddy Simulations provide insight into the unsteady characteristics and coherent vortex structures of turbulent flows. Discrete hole film cooling is a jet-in-cross-flow phenomenon, which is known to produce complex turbulent interactions and vortex structures. For this reason, the present study investigates the influence of these jet-crossflow interactions in a time-resolved unsteady simulation. Because of the broad spectrum of length scales present in moderate and high Reynolds number flows, such as the present topic, the high computational cost of Direct Numerical Simulation was excluded from possibility.B.S.M.E.
Bachelors
Engineering and Computer Science
Mechanical Engineering
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Chen, Youjiang. "Fundamental Aspects of Electrocatalysis at Metal and Metal Oxide Electrodes." Case Western Reserve University School of Graduate Studies / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=case1284390270.
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Gallo, Federico. "Dynamics of sand injections." Thesis, University of Cambridge, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.613651.
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El-Zohry, Ahmed M. "Exploring Organic Dyes for Grätzel Cells Using Time-Resolved Spectroscopy." Doctoral thesis, Uppsala universitet, Institutionen för kemi - Ångström, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-263143.
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Grätzel cells or Dye-Sensitized Solar Cells (DSSCs) are considered one of the most promising methods to convert the sun's energy into electricity due to their low cost and simple technology of production. The Grätzel cell is based on a photosensitizer adsorbed on a low band gap semiconductor. The photosensitizer can be a metal complex or an organic dye. Organic dyes can be produced on a large scale resulting in cheaper dyes than complexes based on rare elements. However, the performance of Grätzel cells based on metal-free, organic dyes is not high enough yet. The dye's performance depends primarily on the electron dynamics. The electron dynamics in Grätzel cells includes electron injection, recombination, and regeneration. Different deactivation processes affect the electron dynamics and the cells’ performance. In this thesis, the electron dynamics was explored by various time-resolved spectroscopic techniques, namely time-correlated single photon counting, streak camera, and femtosecond transient absorption. Using these techniques, new deactivation processes for organic dyes used in DSSCs were uncovered. These processes include photoisomerization, and quenching through complexation with the electrolyte. These deactivation processes affect the performance of organic dyes in Grätzel cells, and should be avoided. For instance, the photoisomerization can compete with the electron injection and produce isomers with unknown performance. Photoisomerization as a general phenomenon in DSSC dyes has not been shown before, but is shown to occur in several organic dyes, among them D149, D102, L0 and L0Br. In addition, D149 forms ground state complexes with the standard iodide/triiodide electrolyte, which directly affect the electron dynamics on TiO2. Also, new dyes were designed with the aim of using ferrocene(s) as intramolecular regenerators, and their dynamics was studied by transient absorption. This thesis provides deeper insights into some deactivation processes of organic dyes used in DSSCs. New rules for the design of organic dyes, based on these insights, can further improve the efficiency of DSSCs.
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Huang, Heming. "Optical nonlinearities in quantum dot lasers for high-speed communications." Thesis, Paris, ENST, 2017. http://www.theses.fr/2017ENST0012/document.
Повний текст джерелаАнотація:
L’évolution actuelle des systèmes de communications optiques est telle que la circulation d’information n’est plus exclusivement limitée par les liens longues distances transocéaniques ou par les réseaux cœurs. De nombreuses applications courtes distances comme les réseaux d’accès où les débits des systèmes amenant la fibre chez l’abonné doivent être maximisés et les connexions internes et externes des centres de données transportent un trafic de données important produit en partie par les applications de type « Big Data ». Les critères imposés par ces nouvelles architectures notamment en termes de coût et consommation énergétique doivent être pris en compte en particulier par le déploiement de nouveaux composants d’extrémités. Grâce au très fort confinement des porteurs, les lasers à boites quantiques constituent une classe d’oscillateurs présentant des caractéristiques remarquables notamment en termes de courant de seuil et de stabilité thermique. En particulier, l’application d’une perturbation optique externe permet d’exploiter les nonlinéarités optiques des boîtes quantiques pour la réalisation de convertisseurs en longueur d’onde performants ou de transmetteurs à haut-débit fonctionnant sans isolateur optique. Ce dernier point est particulièrement critique dans les réseaux courtes distances où l’utilisation de sources modulées directement reste une solution technologique importante.Ce travail de thèse réalisé sur des structures lasers à base d’Arséniure de Gallium (GaAs) et de Phosphure d’Indium (InP) montre la possibilité d’améliorer l’efficacité de conversion non-linéaire par injection optique et de générer de nombreuses dynamiques dans des oscillateurs rétroactionnés et émettant sur différents états quantiques. Par ailleurs, le déploiement massif des systèmes cohérents mais également la conception des futures horloges atomiques sur puces nécessite l’utilisation de sources optiques à faible largeur de raie et ce afin de limiter la sensibilité de la réception au bruit de phase du transmetteur et de l’oscillateur local et induire un taux d’erreur binaire important. La conception de laser à faible largeur spectrale constitue un autre objectif de ce travail thèse. Les avantages de la technologie boites quantiques ont été mis à profit pour d’atteindre une largeur spectrale de 160 kHz (100 kHz en présence de rétroaction optique) ce qui est de première importance pour les applications susmentionnéesThe recent evolution of optical communication systems is such that the transfer of massive amounts of information is no longer limited to long-distance transoceanic links or backbone networks. Numerous short-reach applications requiring high data throughputs are emerging, not only in access networks, where upgrades of the bit rate of fiber-to-the-home systems need to be anticipated, but also in data center networks where huge amounts of information may need to be exchanged between servers, in part triggered by the rise of big data applications. The new requirements in terms of cost and energy consumption set by novel short-reach applications therefore need to be considered in the design and operation of a new generation of semiconductor laser sources. Owing to the tight quantum confinement of carriers, quantum dot lasers constitute a class of oscillators exhibiting superior characteristics such as a lower operating threshold, a better thermal stability as well as larger optical nonlinearities. The investigation of quantum dot lasers operating under external perturbations allows probing such optical nonlinearities in the view of developing all-optical wavelength-converters with improved performance as well as optical feedback-resistant transmitters. This last point iseven more critical since it is expected that short-reach links making use of directly modulated sources will experience massive deployment in the near future, in contrast to conventional backbone links where the number of required optoelectronic interfaces remains relatively modest. In order to do so, the thesis reports on novel findings in GaAs- and InP-based quantum dot lasers such as improved bandwidth and conversion efficiency under optical injection and various complex dynamics with delayed quantum dot oscillators emitting on different lasing states. Last but not the least, the massive deployment of coherent systems as well as the realization of future chip-scale atomic clocks require the implementation of optical sources with narrow spectral linewidth otherwise the sensitivity to the phase noise of both transmitters and local oscillators can strongly affect the bit error rates at the receiver. This is another objective to be addressed in the thesis where the benefits of the quantum dot technology has allowed to reach a spectral linewidth as low as 160 kHz (100 kHz under optical feedback) which is of paramount importance not only regarding the aforementioned applications
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VENTO, OSCAR. "Research on the fluid dynamics of diesel injection systems, design of innovative closed-loop control strategies, assessment of a new flowmeter for high-pressure fluids and 1D modelling of liquid and gaseous flows." Doctoral thesis, Politecnico di Torino, 2021. http://hdl.handle.net/11583/2927462.
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Edwards, Eric. "DEVELOPMENT OF A NOVEL APPROACH TO ASSESS QUALITATIVE AND QUANTITATIVE DYNAMICS ASSOCIATED WITH THE SUBCUTANEOUS OR INTRAMUSCULAR ADMINISTRATION OF PHARMACEUTICALS AND ASSOCIATED PARENTERAL DELIVERY SYSTEMS." VCU Scholars Compass, 2011. http://scholarscompass.vcu.edu/etd/279.
Повний текст джерелаАнотація:
There has been a significant increase in the number of injectable pharmaceutical products over the last decade that have been incorporated into unique delivery systems such as pen injectors, auto-injectors, or pre-filled syringes. The advancement of these delivery systems and the paradigm shift towards administration of injectables in the out-of-hospital or home setting have introduced variables that can affect the bioavailability of injectable drugs and potential pharmacologic outcomes. An approach that allows for the qualitative and quantitative dispersion assessment of an injectable at the moment of tissue deposition coupled with an assessment of systemic exposure parameters could provide substantial information to researchers developing new injectable formulations and associated delivery systems. The overall goal of this research project was to develop an approach for investigating various injection dynamics, more specifically, dispersion dynamics associated with the administration of parenteral pharmaceutical products utilizing delivery technologies designed to deliver drug below the dermis. This was accomplished by first evaluating the safety and usability of computed tomography (CT) scanning as a novel radioimaging approach to assess qualitative and quantitative dispersion parameters in a cadaver study followed by a randomized, controlled, clinical study to assess CT tissue dispersion and the systemic exposure of iohexol, administered subcutaneously by two delivery systems in human volunteers. The primary finding of this work was the demonstration that CT scanning may be combined with a systemic exposure assessment to provide an effective paradigm for investigating dynamics of injectable delivery impacted by a variety of factors, including the choice of delivery system. In this study, iohexol delivered subcutaneously by an auto-injector resulted in notable qualitative and quantitative dispersion differences, including a higher rate of iohexol loss from the extravascular tissue, as well as differences in early plasma exposure as compared to a pre-filled syringe delivery system. The injections and CT scanning were well tolerated with adverse events limited to mild injection site reactions resolving without intervention. This research resulted in a novel local in-vivo(extravascular disappearance), systemic in-vivo(intravascular appearance) correlation approach that could be utilized to assess a wide variety of dynamics associated with injectable drug delivery below the dermis.